Mojo Jojo is the arch-nemesis of the Powerpuff Girls. He was a lab monkey who was caught in the accident that created the Powerpuff Girls, with the explosion that created them generating a shockwave that mutated Mojo Jojo, increasing his intelligence exponentially and giving him super-strength. As he fells shunned by the citizens of Townsville in favor of the Powerpuff Girls, he decided to become a supervillain, determined to conquer the world and kill the Powerpuff Girls. To that end, he uses his immense intelligence to build an arsenal of high-tech weapons and gadgets.
Mojo Jojo speaks in a very eloquent and redundant manner.