Wasn't the whole idea of Plundor that he was from an alternate dimension where 'cutesy' characters were the norm? Why wouldn't the purple bunny in a dimension where Captain Carrot would seem right at home not make sense? And for the record I never considered Plundor "scary" nor did I ever feel there was an intent to make him so. Just as a skeleton head on a body builders physique makes sense for a world where humans are the norm, a giant purple bunny in a dimension where anthropomorphic animals have gone all 'Animal Farm' makes complete sense in context.