Limax

Limax are aliens that tried to infiltrate Vera Tennyson's retirement community.

Appearance
Limax are semi-humanoid blobs, mostly green in color with dirty pink colored organs. They have multiple eyes and they are shown to have no definite appearance, often having extra arms, fin-like protrusions or misshapen body parts.

Diet
Limax like to eat humans, especially elderly humans, saying children are too chewy and need to age more to become "nice and tender".

Powers and Abilities
Limax are able to shift into any form, including humans. They also gain strength from heat, as shown when they are attacked by Heatblast. This is the reason they decided to attack a retirement area in the desert (during the summer). They can also regenerate and in doing so (sometimes), they create a much larger version of themselves.

Weaknesses
Limaxes are deathly afraid of water. Even just a tiny bit of water may kill them.

                                                                                                                                        
 * Limax from Permenent Retirement
 * Unkown name (The Codon Streams DNA sample of a Limax)

Trivia

 * In Ben 10,000, Max was shown to have a robotic arm. In the Ben 10 pop-up edition of this episode, it was said that he had lost his arm in the "Limax Wars 2017". However, that had taken place in an alternate timeline and Dwayne says that this is not going to happen in the Ultimate Alien timeline.
 * Limax goo is seen moving at the end of the episode, hinting at their possible survival and return, but have yet to make another appearance.
 * Limax are mentioned in Ben's dream in Perfect Day, when Lt. Steel tries to convince him that his grandpa and cousin have been replaced by them.