When twins Harvey and Lola are given the school rabbit, Mr Lugs, to look after for the weekend, they're both very excited. That is until the rabbit begins to mutate. Becoming larger, stronger and much more intelligent, Mr Lugs decides the time has come for the bunnies to rise up and seize control. It's up to Harvey and Lola to find a way to return Mr Lugs and his friends to normal, before the mutant menaces sweep across the country - and then the world!