One of the Axolotl at Kainan Highschool's marine lab.
Axolotl are an animal closely related to the salamander who has it's home in Mexico and the area nearby. It's quite a rare creature, almost extinct in nature, though, partly due to alien species having been introduced to its natural habitat.
It's almost blind and kind of lazy you could say, but it also has the amazing ability to regenerate limbs and even brain tissue.