The Incurseans are a frog-like species from a planet that was accidentally destroyed by a Warrior wielding Ascalon who was trying to unite the factions when a war was going on the planet. Since then the Incurseans have been roaming space in spaceships conquering other planets.
The Incurseans make their debut in the episode X = Ben + 2. In the episode the daughter of the Incursean Emperor Milleous is kidnapped. The daughter's name is Attea. Sevenseven kidnapped her for the ransom. The Incurseans are shown to be vicious and destroy Pluto with the Incursean Conquest Ray, threatening to do the same with Earth if Attea is not returned. They also have a commander named Raff who Kevin knew well back when he was a crook and Attea had a personal guard Frolic who was prosecuted by Milleous as he failed to save Attea from Sevenseven.
Attea does return however and reveals that she has promised to pay Sevenseven double the amount of ransom if he helps Attea to overthrow Milleous. Attea and Sevenseven however are defeated by Ben (Who just had a mind-blowing experience with Alien X, his newest alien) as Swampfire, Gwen and Kevin. Milleous then thanks the team for the effort and promises to leave Earth alone.
Incurseans 'Love of War'
In Con of Rath, Sangfroid. an elite commander of the Incurseans who tried to stop Ben's delivery of the Tiffin to king Jarett. So they could stop a peace resolution between Pantophage and Lewoda because "the Incurseans love war." However, Rath ( A transformation Ben was stuck into and who has an aggressive nature) boarded his ship, single-handedly defeating his soldiers. Sangfroid told Rath he'd let them go, but opened fire the second Rath returned to the ship.
Kevin lured him into a black hole in which Kevin out sped him and the Incursean ship was sucked in. His last words were, "I really hate that guy."
Business with Simian and Argit
In So Long, and Thanks for All the Smoothies, Milleous hires Argit to get the Anihilaarg from a Contemelia ship. Argit meets Ben, Rook and the Vreedle Brothers aboard the ship. Argit eventually escapes with the Anihilaarg intending to double-cross the Incurseans and the Incurseans follow Argit down to Earth aboard their ship, with Rook, Ben and the Vreedle Brothers tagging along. The brawl continues to a Smoothy store where the Anihilaarg is accidentally activated and it destroys the entire universe. Ben as Alien X however re-creates the universe and thinking that the Anihilaarg is a dud, the Incurseans leave.
Their Galactic Conquest
Destruction of Peptos XI
In Tummy Trouble, Ben and Rook are flying in space on the Proto-TRUK, making their way to Peptos XI, where the Gourmands live. Suddenly while aboard they are attacked by the Incurseans. Ben wonders what they might be doing and he turns into Big Chill to fight them. Ben and Rook in the ensuing fight crash down to Peptos XI where they find the Gourmands fighting an army of Incurseans. Ben turns into Echo Echo and using his Wall of Sound he defeats the Incurseans.
The Murk Gourmand leader and Perk Upchuck leader start arguing about what to do about their Queen who has been kidnapped by the Incurseans and whether they should execute Plan Omega or not. The Murk Upchuck leader decides to take an army and rescue the queen with Ben agreeing whereas the Perk Upchuck leader decides to face the Incurseans head on with Rook agreeing. They go their separate ways with Ben and the Murk army invading the Incursean main ship where Attea has held the Queen hostage. Meanwhile, Rook and the Perk army start facing the Incurseans as Rook and Ben start thinking that they should have listened to each other.
While the Perk army is fighting the Incurseans, Rook notices a black tank rolling up and then he sees Ben as Kickin Hawk aboard the Proto-TRUK with Attea tagging along. Ben transforms into Water Hazard and manages to defeat Attea while Rook destroys an Incursean tank. The Murk and Perk armies now united as their queen is back fight ruthlessly and force the Incurseans to retreat. The queen commands the Gourmands to execute plan Omega which is revealed to be eating up their own planet and then going to a new planet. Meanwhile, Attea lies to Milleous telling him that Peptos XI was destroyed on her orders so as to send a message throughout the entire galaxy. Milleous is happy at this and prepares for his other plans.
Attempt at assassinating Vilgax
In Vilgax Must Croak, the Incurseans plan to take over Vilgaxia, Vilgax's homeworld. But for this they must first assassinate Vilgax and so Milleous sends Attea to capture Vilgax and execute him. Attea hires Sixsix, Sevenseven and Eighteight to help her. Meanwhile, Ben, Rook and the Alpha Squad are escorting Vilgax to Incarcecon, which has been emptied because of Vilgax . Their spaceship is attacked and they crash at Incarcecon. Ben starts beating up Vilgax and accuses him of foul play though Vilgax denies.
Suddenly, Attea arrives with the mercenaries and they start shooting lasers at Vilgax, Ben, Rook, Hobble and the rest of the Alpha squad. Ben and Vilgax team up together and escape from the Incurseans though they are still stranded on Incarcecon. Vilgax and Ben have a heated argument with each other which culminates with Attea and Eighteight finding them and attacking them. Vilgax convinces Ben to release him from his shock manacles so that he could help to fight the Incurseans. However, Vilgax is quick enough to double-cross Ben and escapes through the chute leaving Ben to deal with Attea and Eighteight.
Ben manages to escape by using Terraspin and finds Vilgax running frantically. He reactivates the shock manacles and Vilgax is now once again a prisoner. As they head to the other rooms they find Attea along with all the mercenaries and she gloats how the plumbers have been killed by her henchmen. However, Rook and the Alpha squad are safe and together with Ben start battling Attea. Attea decides to use a Techadon Dissipator to blow everyone away. However, when she fires it at Ben, Vilgax comes in the way, saving Ben. Ben turns into Gravattack and manages to defeat Attea and he turns back into his human form glad that everything went okay.
Suddenly, Vilgax shocks Ben revealing that his heroic act of saving him was a ruse so that he could become free from the shock manacles. When Ben wakes up, he is informed by Max that Vilgax tried to steal the Omnitrix but when he saw Attea and the mercenaries stirring, he fled from the scene. Ben is disappointed as he let Vilgax, Attea and the mercenaries get away but Max tries to cheer him up. Meanwhile, Attea contacts Milleous and Milleous tells her that because of her failed attempt at assassinating Vilgax the people of Vilgaxia put up a fight and they had to flee. He warns Attea of not failing him again with Attea scowling.
Plumbers' Rescue Mission
In Rad, Magister Arnux and his plumbers are stranded on Terminus III with their spaceship destroyed. Arnux comments that nothing is safe in Incursean territory. The scene shifts to the Plumber Headquarters where Max is telling Ben and Rook about the situation. Rook comments that Terminus III occupies the space territory of the Incurseans and it has the most toxic atmosphere anywhere in the galaxy. Together Rook, Driba and Blukic comment that there is only one cure of this toxic atmosphere - The fresh venom of a Gracklflint.
The scene shifts to the Undertown where Ben as Diamondhead along with Rook cage a Gracklflint. Together they go to the Black Hole where they meet Rad Dudesman, who would be escorting them to Terminus III. Rad has a well known reputation and is feared by many. The scene shifts to the group boarding the Lovely Duck, the ship in which they would be going. It is operated by Pyxi, Rad's ship's AI. While on space the alarm goes of revealing there is an intruder.
Ben turns into AmpFibian and locates the intruder, Pax, who is an alien right activist who wants to free the Gracklflint. It is revealed that Pax has freed the Gracklflint, much to the dismay of the group. The creature starts thrashing around the ship but it doesn't attack Pax. Angered, Ben turns into Eye Guy to search for the creature. Meanwhile, aboard the Incursean ship an Incursean informs Raff about the Lovely Duck however Raff orders not to vaporize the ship, wanting to give a full report to Attea. Aboard the Lovely Duck, Ben manages to trap the Gracklflint by using Bloxx however he had to stop Rad from killing it thereby leading to its escape.
Ben and Rad prepare to capture Gracklflint but Pax intervenes. It is revealed that the reason why the Gracklflint is not attacking Pax is because it loves to eat Florauna's seeds. By this deduction, the group is finally able to capture the Gracklflint. However, Raff appears on a transmission and demands a search of the ship. Back at the captain's room Rook reveals that the weapons were destroyed by the creature and the Incurseans are coming to search the ship. By turning into Grey Matter manages to converse with Pyxi and Pyxi reveals that the Lovely Duck won't be able to face another standoff. The group then plans to fix the ship.
The Incurseans come and find Pax being 'himself' at the cargo bay. Major Glorff takes him and a large box to the Incursean ship. Meanwhile, Major Glorff continues inspecting the ship and finds Rad. He comments " It's only a duck" when the 'duck' takes out weapons causing the Incurseans to back off. Meanwhile, aboard the ship Raff opens the large box and the Gracklflint is released. It starts causing havoc on the Incursean ship. Ben and Rook succeed in fixing the ship and releasing it from the Incursean's grip and Rad manages to drive the Incurseans off his ship. The group pick up Pax and move on but Pax demands to know why they left the Gracklflint behind. Ben tells him to wait for it.
Raff appears on another transmission and tired by the chaos, agrees that if the group take away the creature he will leave them alone. Taking back the Gracklflint the group arrive at Terminus III and rescue the plumbers. The plumbers are treated and the group flies off having completing the mission and having humiliated the Incurseans.
Invasion of Revonnah
In While You Were Away, the Young One is seen flying a harvester having gotten good at it. Rook Shar complains to Wat-Senn, the plumber stationed on Revonnah but he shrugs it off. Rook Shar scolds him and tells him that he never does anything. Watt agrees and tells that's why he is stationed here. Suddenly, Incursean ships arrive and nearly shoot down the Young One. The scene shifts to Earth where Rook and Ben are chasing down an unknown harvester. They succeed in crashing it and see the Young One coming out of the wreckage.
Rook is surprised to see his younger sibling. He asks when he learned to pilot that thing and he gets the response that while he was away. He suddenly turns his attention to Ben and tells him that Revonnah has been invaded and he came for their help as soon as the invasion started. Rook praises him for that and the three of them head to investigate. Back at Revonnah, Attea is seen talking to Dr. Psychobos who she has freed from prison so that he could help the Incurseans in taking over the galaxy. The two don't seem to get along. Dr. Psychobos is holding a test tube and says he needs all the Amber Ogia available for his research to which Attea agrees. Meanwhile, in space the group is heading to Revonnah and when they land they notice that everything is a bit empty.
They then meet Rook's family and Rook Da invites them all for dinner, much to Ben's surprise. Rook Da starts denying that anything strange is happening and much to the group's surprise the family show a distaste for Galvans and start using contractions. Ben asks about the new pipeline that they found when they had landed and Rook Da says that it's for transporting Amber Ogia. Ben asks whether the Incurseans have invaded or not and the family looking uneasy, deny the fact. Ben, having enough decides to search the planet on his own.
When they go for searching they notice a group of Revonnahganders nearby. They start attacking the group and Ben turns into Ball Weevil to escape. The group runs into Muroids but Rook tells them not to worry as they are timid. However Rook Shar and Wat-Senn say that they are not timid this time revealing the Muroids to be disguises. Young One is happy to see his sister and tells her that everyone have been acting strangely. Rook Shar agrees and tells that they wanted to fight but they knew it would be a losing battle and so they hid underground. She also tells them that they sprayed Amber Ogia on the residents and they stopped battling as if in a mind control.
The Incurseans have been harvesting a lot of Amber Ogia and Ben wonders what they are gonna do with it. Meanwhile, more Amber Ogia is being delivered to a tower like structure, where Attea is excited that they have succeeded in controlling so many beings using the Ogia Concentrate that Dr. Psychobos made. The Cerebrocrustacean tries to attack Attea, but she easily subdues him leading the mad scientist to beg for mercy. Attea tells him to watch it. Back in the caves, while scaring way some Muroids Rook Shar and Watt are sprayed with Amber Ogia and come into the control of the Incurseans much to the group's horror.
The mind controlled beings start attacking the group and Ben turns into Gravattack to trap them. Ben tells the Young One to stay with the two and he and Rook head off to the place where the Amber Ogia is being extracted where they meet Attea. Rook starts using the phrase " And I use the term loosely " through which Ben deduces that this is Dr. Psychobos' doing. The crab arrives on a ship and starts attacking the team. Ben turns into a new alien Astrodactyl and using his powers starts destroying the tubes containing Amber Ogia concentrate leaving only one tube enact. Attea starts grabbing the tube and ends up battling Rook.
Rook, enraged by the way how Dr. Psychobos has insulted his culture and people, drops the last tube. However, there is still a little amount of Amber Ogia concentrate left. Attea grabs it and flees on a ship with Dr. Psychobos. The Revonnahganders are free from the mind control and start attacking the remaining Incurseans. Rook Da assures that they can handle this one on their own and tells Rook that Shar wants to become a Plumber. Hailing Rook as a hero, the Revonnahganders bid Ben and Rook farewell. Meanwhile, aboard an Incursean ship Attea and Dr. Psychobos prepare for their final plan - Earth.
The Battle for Earth
Ben has been causing problems for the Incurseans from time to time, so it would be better if the Incurseans just eliminate him. Also, Earth is the ideal center place for taking over the entire galaxy so the Incurseans make Earth their next target. The two parter episode, The Frogs of War: Part 1 and Part 2, focuses on their invasion of Earth and the resistance by the residents.
In The Frogs of War: Part 1 Ben is seen fiddling with his Omnitrix when suddenly aliens from Undertown start arriving and fleeing from the Earth as they believe that the Incurseans are coming. Ben and Rook agree that most likely Earth would be the next target of the Incurseans. Some more aliens emerge from the Undertown thereby revealing the existence of Undertown to humans. Back at the Plumber HQ the problem is being discussed. Max tells Ben and Rook that Incursean ships have indeed cornered Earth. However, he also tells them that a shield is protecting Earth which would buy them some time.
Ben is sent to a press conference where he tries to calm down the Humans who have learned about the existence of aliens. Will Harangue is also present and he tries to thwart Ben's calming down of the humans and how Ben was a traitor to the Earth. Unfortunately, due to Ben's fiddling of the Omnitrix the Randomizer function of the Omnitrix unlocks and it rapidly causes Ben to turn into different aliens in a short span of time. This unintentionally causes damage to buildings and other property. Meanwhile, the Incurseans have been trying to communicate with Earth but Attea tells her dad that the shields are preventing communication. Milleous however threatens Attea if she speaks out of term again while Dr. Psychobos teases Attea. Attea than attacks the crab and the Incurseans manage to breach the shield and they begin their assault. Ben finally manages to calm everyone down and tells the humans to feel respect whenever they think of aliens. Unfortunately, that is when the Incurseans strike.
Ben, who has turned into Water Hazard at that time tries to spray water on the ships, but to no avail. He swiftly dodges an Incursean beam and turns into Astrodactyl and starts knocking down Incursean ships. In midair, Astrodactyl turns into Snare-oh and is attacked by an Incursean ship. Attea starts to battle Snare-oh but Ben turns into Rath and punches a hole into the ship. The ship starts to crash and Ben turns into normal. Ben is rescued by Rook who is then taken to the Plumber HQ. Meanwhile, Dr Psychobos thinks that it would be better if they tell Milleous about it but Attea yells at him.
Back at the Plumber base, the plumbers are running around frantically as Milleous tells everyone that he is the ruler of Earth as Incurseans have invaded every part of the planet. Max asks Driba and Blukic how the Omnitrix is doing with the Galvans saying that the Randomizer function has been activated. Ben yells that he knows that with Blukic hitting the watch with a wrench. Max then decides the Plumbers better attack Milleous hoping to disrupt his communications with the rest of his army. Ben wants to join in with Max declining. Meanwhile, Attea's ship is being attacked by plumber tanks with Dr. Psychobos saying that their defense force is getting away with Attea saying Milleous can handle himself while she needs to do something else.
Meanwhile, the forces led by Max attack Milleous' ship with Milleous gloating and firing back. Back at the base, Attea and Dr. Psychobos are searching for Ben but fail to find him. Rook's Proto-TRUK is hurt and Max tells Rook not to land. Suddenly Ben's voice is heard from the back and Ben turns into Bloxx as the Proto-TRUK crashes into Milleous' ship making Max think that Ben and Rook are dead. Meanwhile, aboard Milleous' ship, the two have survived the crash. Rook scolds Ben saying that he was to use Big Chill to sneak inside with Ben saying Bloxx is better. Bloxx turns back into Ben who is happy that the Randomizer function has stopped working. Ban hoping to turn into Humungousaur, turns into Nanomech instead and Nanomech uses it's energy blasts to knock down Incurseans heading towards them.
Rook manages to defeat the rest of the soldiers as Nanomech turns back into Ben. Rook notices that whatever Driba and Blukic did shortened the Omnitrix's transformation time. Max angrily attacks Milleous still thinking Ben and Rook are dead as Milleous orders his soldiers to take down Max. Suddenly Ben as Four Arms appears along with Rook and helps Max. Ben is grabbed by Milleous who threatens to kill Ben if Max doesn't call of the attack. Suddenly Incursean ships start attacking Milleous' ship as Milleous notices Rook messing with the controls. Ben turns into Big Chill to escape Milleous' grasp. Big Chill then freezes Milleous, turns back to normal, and tells everyone not to stop firing. Inside a base, Attea is yelling that she is taking over and tells them to fire at Milleous' ship. Ben and Rook are talking, while Milleous breaks free from the ice and he says that he threatens to destroy everything.
Ben transforms into XLR8 and runs away from Milleous for a short time before turning back to normal. Ben then turns into Humungousaur and lifts up Milleous. However, the Omnitrix times out and Milleous lands on top of Ben. Milleous attempts to crush Ben by leaping up high and falling back down but Ben transforms into Crashhopper and rams Milleous in midair, causing him to leap all around the room. Milleous' ship soon lands on Earth and Ben turns back to normal with Milleous landing on Ben, but Rook then handcuffs Milleous.
Outside of the ship, Max and Attea are both holding up their guns and Max says that he has her army outnumbered. However, Attea then shows more of her Incursean ships, having the Plumber's ships surrounded, but Ben appears behind her, telling her to call off the ships or Milleous will die. Attea then says that Ben doesn't have the guts to do it, and Milleous then tells Ben that he will let him go with the condition that Ben has to leave Earth and never come back. Ben asks why and Dr. Psychobos soon presses a button which causes a device to activate. Attea asks Ben if he was wondering what she did with the mind control juice and Ben replies, saying he does.
Soon, large mutated To'kustars begin raining down from the sky on nearly all parts of Earth and Milleous tells Ben that if he doesn't leave, the Mutant To'kustars will begin destroying Earth. Ben doesn't want to, but Max tells Ben to. Ben is shocked, saying he won't let them win, but Max says he thought he lost Ben before, and with Ben leaving Earth, he will know Ben is still alive. Ben reluctantly gives himself up and Attea locks him in an Incursean space pod. Milleous gloats as Max and the other Plumbers are being boarded on Incursean ships. Will Harangue reports on how the Incurseans have taken over Earth, but proudly says how their biggest threat Ben has been sent away. Ben is soon blasted into space, with Harangue telling Ben, "goodbye and good riddance."
With Ben exiled in space and things not looking good, Ben's old team consisting of Gwen, Kevin, and Rook continue fighting the Incurseans with the help of Argit. Will Harangue meanwhile who has an affiliation with the Incursean is speaking good about their new benevolent lords as they blow up the white house. The Reconnaissance tries to smuggle weapons, but they are caught and are forced to flee. Regrouping at Mr. Baumann's shop, they discuss what to do when suddenly Argit points out that they should capture Dr. Psychobos as he is the one who is controlling the Way Bads.
After agreeing, the group plan to attack what they think is Dr. Psychobos' personal convoy when Gwen realizes that this is not Dr. Psychobos' convoy but it's a trap - Argit has betrayed them to the Incurseans. As the Incurseans led by Attea are about to capture them a tall, lean Incursean named Bullfrag comes to the aid of the team. He rescues them and leads them to a spaceship where Kevin knocks Bullfrag out. When he comes to his senses he sees the group has him and he insists that he is an ally. After a scan, Gwen says that he's okay while Bullfrag asks for smoothies from Blukic. As they all follow Bullfrag's plan to free the plumbers and find Dr. Psychobos, they manage to get inside the Plumber HQ as Bullfrag brings them in as 'prisoners'.
Once inside, Rook and Blukic manage to free Argit (unintentionally), Driba and a dehydrated Magister Patelliday. They realize that they need to free Max to mount a resistance. At Max's cell, Bullfrag picks up Max calling him 'Grandpa' while Max calls him 'Ben'. Kevin is shocked and then he becomes angry when he learns everyone suspected Bullfrag to be Ben. Ben explains that when he was exiled, he found that his wrist was loose. Azmuth then came to his rescue, unlocked Bullfrag, the DNA sample of an Incursean and gave Ben the life form lock so that he could stay as Bullfrag without timing out.
Attea then comes up behind the group and starts saying that how her daddy is gonna be mad when Bullfrag starts flirting with her, Attea gets ashamed as she has a crush on Ben as Bullfrag when she is knocked out by Gwen. Disgusted, Kevin asks what was that for as Ben replies it's the DNA. Knowing that his cover has been blown Ben deactivates the Life Form Lock and transforms back into his human form. From elsewhere, Rook contacts the group where he, Driba, and Blukic have been attempting to subdue Psychobos, and confirms that he also suspected that Bullfrag was Ben (to Kevin's annoyance). They explain that Psychobos summoned a mutant To'kustar, headed in their direction.
While Way Big is caught in a headlock by the Way Bads, Argit inadvertently knocks one out with his spikes in his escape. Rook, Driba, Blukic and Patelliday drive by, shooting the Way Bads with a Null Void Projector and sending them to the Null Void. This allows Way Big to fire his own laser beam to intercept Milleous' conquest ray, forcing the Incursean emperor to escape before his ship is blasted to bits. Rook's group leaves to catch all the Way Bads on Earth, while Ben, Kevin, Gwen, and Max confront Milleous, with Attea and Psychobos in chains.
Milleous angrily states that he still has his regular Incursean army, but Max reminds him that Milleous is now under capture. From behind, Attea picks her handcuffs free, declaring that with her father arrested, it now leaves her in charge of the Incurseans, which was her master plan all along - much to the surprise of everyone present.
Attea reveals that she was the one who loosened Ben's locks on his wrist so he could escape, knowing that he would return to Earth and overthrow Milleous in order to save Earth, thereby defeating her father for her. Ben is mortified at the extent of Attea's vicious plot, but Attea retorts that ever since their first encounter, Milleous kept her under close watch, forcing her to take drastic measures to usurp her father's position. Attea then demands that Ben let her go free, in exchange for the Incurseans pulling back to their original territories, goading Ben on since she knows that the heroes want to avoid a war. Max and Ben grudgingly accept Attea's terms as she offers to pay for damages, having secured her position of power. Milleous is torn between anger and pride for Attea as he is taken away.
Before leaving, Attea briefly flirts with Ben, asking him to join her as Bullfrag. Disgusted, Ben declines as Attea shrugs him off, stretching her tongue to kiss him at the back of his head. As Attea's forces take off, Rook calls him to say that news of Ben's latest heroic exploits have spread through the galaxy, and that the Incurseans have pulled back. Relieved that the war is now over, Ben wonders whether any Mr. Smoothy stores had been damaged as the episode ends.
The war against the Incurseans resulted in them taking over the Earth for over a month, the most by any other villain. Due to the invasion of the Incurseans, humans and aliens learned to work alongside together and both of them helped in the resistance against the Incurseans. This led to the accepting of aliens by humans and now both aliens and humans live together. Also, because of the peace treaty that Attea signed with the Plumbers, Attea is now the ruler of the Incurseans with Milleous now in plumber custody, all according to Attea's plan.
Because she wanted to ascend to the position of High Empress, Attea went looking for a husband which led to the events of Catfight in which Attea forms a rivalry with Princess Looma Red Wind of the Tetramands on their quest to claim Ben as their husband. Eventually, at the end of the episode Ben convinces both the rulers that they don't need a husband to ascend to the throne and Attea goes back to her residence to complete the process of ascending to the throne, now to be known as Lord Empress Attea, light of the Incursean empire, destroyer of galaxies, keeper of the conquest ray, all beings tremble- since the speaker is usually cut of at this point, the full title is unknown.
Even though the Incurseans have signed a peace treaty with Earth, they still loom as a large threat to Ben and his team.