In Alien Force, Manny was indistinguishable from a regular Tetramand with the exception of his head, which seemed more oblong, and height. He wore a sleeveless black-green outfit, black wristlets and black pants with green pockets.
In Omniverse, he has more humanoid traits. He has five fingers and he is scrawnier, especially his lower arms, and he now no longer has his robotic hand on his lower left arm. He also has a bigger chin and slightly darker skin color. Since he became an official Plumber, he wears a Plumber Suit.
Before his encounter with Servantis, he was a regular human. He was a thin, Afro-American kid with an afro. He had big, dotted eyes, thick eyebrows and dark lips.
After his amalgamation, he looked like a regular young Tetramand with more averaged sized eyes.
Manny is hot-headed and rebellious, often willing to fight even when it may be not necessary. He enjoys fighting, and can sometimes become rude toward his teammates, especially Pierce, who he doesn't accept as a field leader, and Alan, whom he would like to be more aggressive. He also once argued with Kevin, and was shown to be the less respectful of the Plumbers helpers toward Ben. However, he is also shown to be devoted to Max, refusing to reveal his identity to D'Void and willing to help him when he was seemingly attacked by Ben. Despite their differences, Manny has shown concern with his team as he was willing to sacrifice himself so his team could escape (although he'd forgotten their ship had been destroyed).Manny serves as Kevin's mirror on his team, and share many character traits. He is cocky, abrasive and has difficulty expressing his personal feelings. However, Manny lacks his mirror's laid-back attitude, often permanently angry and insulting to even his own allies, earning him the dislike of Kevin and Ben and forcing Helen to act as peace-keeper. His anger has lead him to cross the line at times: in his first appearance, Manny tried to force Ben, Gwen and Kevin to reveal themselves as DNAliens by shooting the wheels off a nearby tanker. The tanker crashed by a fuel station and caught fire, endangering the lives of the driver and innocent bystanders. When confronted over this, Manny shows no remorse for the act, proving he is more concerned with fighting bad guys than saving lives.
Manny shares a love-hate relationship with Helen. While his hot-headed attitude, when confronted to Helen's wiser personality, cause them to often fight, he is shown to truly care about her, being once willing to attack Ben after he hurt her in Above and Beyond.
Manny was actually born as a human who was taken to the Null Void by Servantis. He used Kevin's powers and a Tetramand to create Manny's actual form. He, along with Helen, Alan and Pierce formed a group, named Amalgam Kids, and they were used by Servantis to do "nasty things". After they failed in their ultimate mission - destroy Ben Tennyson - their memories were wiped by Servantis.
Years later, Manny became part of a team of young Plumbers apprentices, the Plumbers' Helpers, which included him, Helen and Pierce. However, they had little knowledge of the technology they used, and Pierce was sucked by a Null Void Projector they had confused with a disintegrator weapon. Believing that Pierce was dead, Helen and Manny continued the work, capturing many kinds of aliens they confused for criminals and sending them into the Null Void. Though part of those they captured were DNAlien, most of them were just innocent aliens.
In Plumbers' Helpers, they eventually encountered Ben, Gwen, and Kevin. Despite Helen's doubts, Manny immediately assumed they were DNAliens, and they captured Kevin in order to interrogate him, then send him in the Null Void. However, Ben and Gwen came to free Kevin and were eventually able to explain to them the truth. After learning the error of their ways, Helen and Manny travel into the Null Void to look for those they've wrongly imprisoned.
Manny returns from the Null Void in War of the Worlds: Part 1 and War of the Worlds: Part 2 and helps Ben and the others fight off the Highbreed. In the end, he becomes, along with Alan, Cooper, and the other Plumber's helpers, a pupil of Max.
Manny appears again in Vengeance of Vilgax: Part 1, where he, along with Max's other pupils, tried to defeat Vilgax, but Manny was easily defeated and threw onto a tree.
In Above and Beyond, the Plumber's helpers came on a satellite in order to save Max from a seemingly brainwashed Ben. Manny was the more willing to fight Ben, but, when he eventually found him, was easily defeated by Rath. During their fight, they accidentally damaged the gyroscope, causing the satellite to start falling towards London. By working as a team, the helpers were able to neutralize Humungousaur and throw him into space. They then tried to sacrifice themselves to prevent the crash, but didn't need to, as it was revealed all of this was just a test to see if they were worth being true Plumbers, except the falling part.
He returned in Weapon XI: Part 1, when he and Helen were on Khoros taking Gorvan into custody. However, they were attacked by Phil and Leander. Fortunately, Ben, Gwen and Rook arrived just in time and saved them. Ben took them to Kevin's garage where Alan explained that they were used by the Rooters and had their memories wiped. When he came to the Null Void to help Kevin, he, Helen and Alan were brainwashed by Servantis and were commanded to destroy Ben. In the battle, he defeated Rook but was quickly defeated by Alien X who was controlling Leander's body. At the end of the episode he, along with the others joined the Rooters and was commanded to hunt down Ben.
In Weapon XI: Part 2, just as they were about to destroy Ben, a mutated Kevin grabbed Servantis, destroyed the crystal on his forehead and used Feedback's powers to free them from his control forever. He and the other Amalgam kids then returned to Earth.
Powers and Abilities
Manny possesses most of Four Arms's powers, which include enhanced strength, enhanced durability and four arms, along with a robotic prosthetic hand in place of his lower left hand.
In Plumbers' Helpers he is shown to be quite good at rock-climbing, able to scale a wall quickly without any problems.
Manny is quite capable of melee combat, and would gladly engage an enemy.
In addition to his powers, Manny usually uses four blasters as his weapon.
Manny seems to lack the speed of other typical Tetramands, which puts him at a disadvantage against faster opponents like Rath.
Unlike a full Tetramand, Manny can't withstand fire.
Ben 10: Alien Force
- Plumbers' Helpers (first appearance)
- War of the Worlds: Part 2
- Vengeance of Vilgax: Part 1
- Above and Beyond
Ben 10: Ultimate Alien
- The Ultimate Enemy: Part 2 (flashback; cameo)
Ben 10: Omniverse
- The Rooters of All Evil (first re-appearance; flashback; cameo)
- Weapon XI: Part 1 (flashback and present)
- Weapon XI: Part 2 (flashback and present)
- Triple Threat
His name is a pun. His first name 'Manny' comes from the word "many" which is a reference to his arms. His last name, "Armstrong" is made up from two words 'arm" and "strong", arm again is a reference to his arms and strong is a reference to his physical strength.
- According to Dwayne, Manny's mother was a Tetramand, but she died when Manny was still a baby. This, however has never been stated on-screen.
- In the episode The Rooters of All Evil, this has been retconned.
- In the episode Weapon XI: Part 1, Manny is now a full pledged Plumber, and the lower right hand that he lost is now restored, or replaced.