Episode Title:Dexter's Rival / Simion / Old Man Dexter.Episode Description:Dexter's Rival: Mandark Astronomanov, a new student at Dexter's grade school, seems to be superior to Dexter academically. Mandark compels Dexter to shut down his lab so that Mandark's lab can gain more power.
Simion: Monkey encounters Simion (Maurice LaMarche), an intelligent anthropomorphic chimpanzee who seeks vengeance on humans for turning him into his current state.
Old Man Dexter: After being banned by his parents from watching a late-night movie due to his youth, Dexter uses his technology to age into adulthood. Dee Dee tampers with his machine, causing Dexter to turn into an elderly version of himself.