|An article about EVOs can also be found on the Generator Rex Wiki.|
|Exponentially Variegated Organism|
|Home World||Rex's Earth|
|First Appearance||Ben 10-Generator Rex: Heroes United|
The appearance of EVOs are random, as the active Nanites altered their appearance at the molecular level, thus giving them various powers and abilities.
- Rex Salazar
- Bobo Haha
- Black Knight
- Alpha Heatblast
- Alpha Four Arms
- Alpha Humungousaur
EVO stands for Exponentially Variegated Organism.