Gummy

Gummy is Pinkie Pie's pet alligator, so named because he has no teeth. He first appeared in the episode Feeling Pinkie Keen, where it's revealed that he gets into Pinkie's bathtub often enough to merit a warning twitch in the pink Earth Pony's arsenal of warning feelings.

Although Pinkie calls Gummy her pet, the little alligator is agressive enough to make repeated attempts to bite his owner. This does her no harm, and she doesn't even react.