The Witch Doctor is the secondary antagonist of Ribbit. He is the bigger bad through the story although he just makes minor appearances near the end of the film.
Before the release of the film, he was rumored to be the main antagonist, just to keep as a suprise the role of the true villain.
Role In The Film
He first appeared ambushing the poisonous frogs and catching the ones who didn't hide behind the bushes. He was later seen planing to kill the princess behind her back. At the end of the film he got tangled up with the crocodile Kai and both were arrested.
It was seen that the princess trusted him, what made him take advantage of her feelings. As a payment, he was arrested by his own guards.