Watch Online Free FlixHQ. Cartoon worlds collide in this hourlong adventure starring whiz kid Jimmy Neutron and Timmy Turner from "The Fairly OddParents." When the boys duel over Cindy Vortex, it draws the attention of Jimmy's archenemy, Prof. Calamitous, who teams with Wanda and Cosmo, forcing Jimmy and Timmy to work together to save the world from the all-powerful villain.