Ben 10

2. Fish alien; used sparingly due to not being able to sustain much air on land
5. Flying alien; particularly gross
6. Small but incredibly smart
7. First alien accessed; powers reversed when sick
9. Electric alien; was used highly before being destroyed
12. First alien unlocked; first thought to be useless before stopping threat
13. Fast alien; name is pretty obvious
14. Only alien originally not from roster; used to seal breach in space-time
16. No eyes; relies mostly on sense of smell
17. High tech alien; can merge with machines
19. First alien unlocked off-screen; First seen in alternate opening of Secret of the Omnitrix

1. First transformation to go rogue; real name is Zs' Skayr
3. Alien was not transformed in the same episode it was unlocked, first alien to be renamed
4. High durability with powers connecting to rock
8. Frankenstein alien; has electrical powers
9. Intense strength; red skin
10. Second transformation to go rogue; was only available once
11. First alien sampled; only transformation that took hours to fully transform
15. Elastic arms; plant alien
16. Large alien; name say it all
17. Only alien that two separate races; successfully defeated Forever King
18. Powers of self-duplication; time-out took longer due to missing clone