Aka one of the few things you'd think of - if not immediately - when thinking of the words "green" and "animals" together in one of your dreams.

Except these animals aren't simply cartoony animals, but rather ones that have gained sentience and the ability of human speech thanks to a mutating gas that was spreading in the lab room all 4 of them were in during the accident. Since they didn't think the lab could be their home, anymore, they escaped to the nearby swamp where they live in a tree (Elle and Greg) and the lake nearby (Fred), as well as between the two (Belle).

They're also the same size - size being that of dwarves.