Supervillian that steals everything they can get a hold of and breaks the rest, usually for lulz. A sweetbunny is classically found on irc networks high out of its mind on psychedelic drugs.
(Usually occurs in gym class and/or workout sesh.) When a fat male works out with a shirt on and sweats so much that it makes a sweatprint that looks like a bunny. (The two ears would be the moobs or man boobs and the head would be the stomache region)
Girl 1: Ew look at dave he is dripping with sweat.
Girl 2: Ya i know he has a sweatbunny too, wait until he turns around