Libby Folfax as a villainous dictator
Libby Folfax (Crystal Scales) is a recurring protagonist on the Nickelodeon series Jimmy Neutron. She also appeared as a villainess in the Season 3 episode, "The Tomorrow Boys" (airdate June 17, 2005).
In the episode, Jimmy Neutron and his friends, Carl Wheezer and Sheen Estevez, dropped off their presents to Libby for her birthday party before going back to Jimmy's lab to test out his newest invention: the Chrono Arch, a time machine allowing them to go to the future, where they saw great lives for themselves. But unbeknownst to them, Jimmy's gift for Libby (a perfume) had accidentally been replaced by Carl with another experiment of Jimmy's: Megalomanium, a chemical that caused anything exposed to it to become viciously power hungry.
After opening her gift in the present, Libby became exposed to the Megalomanium, resulting in her future self becoming the evil dictator of Retroville. When Jimmy and his friends went into the future, they found it grim and ominous and were confronted by a robotic cop acting as Libby's evil minion, confronting them for not watching Dance Gazebo (one of several programs that were required viewing under Libby's rule). The robot called Libby via hologram, with Sheen (who had a recurring crush on Libby) being taken by her beauty. When informed by the robot of the gang's "crimes", the ruthless Libby sentenced them to one hundred years of hard labor.
Jimmy and his friends, however, were able to escape to the present--with Libby's robotic minion giving pursuit--and destroy the Megalomanium before Libby was exposed to it. But in the process, all of Libby's gifts were destroyed by the three protagonists and her house was damaged, angering Libby to the point of ordering the boys out of her house. But later, after learning what had been happened, Libby approached Sheen as he wrote a lengthy apology letter and thanked him for helping save her. She then walked Sheen back to her house and promised him a date at the Candy Bar--after he, Jimmy, and Carl finished cleaning up her house.