The Ballad of the Creeper - S1.E33

Following the blueprints of the scientist Peter Applebottom, the Creeper has invented a device that can corrupt the Corespore. This turns all Animalians, including Alex and Zoe, into ninnies. Gorillas are the only species not affected by the corruption, so G'Bubu leads the quest to restore the Corespore and free Animalia from ninni-ness.