The Monster Rabbit appears as a completely normal, small, harmless rabbit with mainly white fur, long black ears, a black-tipped white tail, and big beady black eyes with white pupils. However, when it becomes aggravated and begins to cause mayhem, it bears its unnatural sharklike fangs and long, snakelike forked tongue.
This creature, which appears to be a cute and innocent bunny at first, turns out to be an extremely powerful, vicious, and dangerous monster with frightfully destructive power despite its small size. It can breathe huge jets of pink flames, smash large buildings to pieces with a single kick, leap on top of skyscrapers, shoot vaporizing laser beams from its eyes, and lift and throw heavy objects (such as a car). It is revealed to have a mouth lined with razor-sharp sharklike fangs, and a snakelike forked tongue; it hisses with fangs bared menacingly and long tongue flickering, much like a viper. It seems to posses advanced intelligence as well, a willfully vengeful and cruel demeanor, and a morbid thirst for destruction.
At the time of the Monster Rabbit’s appearance in Tremorton, Jenny was low on power (from slacking off to let Misty do all the crime-fighting). Misty refused to fight the Monster Rabbit, as Tremorton had stopped paying her for her heroics. As a result, the Monster Rabbit rampaged in the city, and the fatigued Jenny was helplessly pummeled by the monstrous lagomorph — only to then be attacked at the same time by her former friend, Misty, as the two were quarreling.
The Monster Rabbit was hurled into the sky by Misty (because it was getting in her way as she attacked Jenny), and it seemed to have disappeared. However, at the end of the episode, it was revealed that there were many more of them, as rabbits are known to multiply rapidly. It is unknown where these mutant creatures originated from.