Dexter's Laboratory (Season 0)

He skips grades. She just skips

Dexter, a boy-genius with a secret laboratory, constantly battles his sister Dee Dee, who always gains access despite his best efforts to keep her out, as well as his arch-rival and neighbor, Mandark.

Dexter's Laboratory (Episode 1)
Air date: 1995-02-26
Runtime: 7 min
Overview: Dexter and Dee Dee test his latest invention: a device that turns people into animals, which yields crazy results.
The Big Sister (Episode 2)
Air date: 1996-03-10
Runtime: 7 min
Overview: When Dee Dee eats an experimental cookie of Dexter's design, she grows extremely tall and makes the city her dollhouse, leaving it up to Dexter to don his giant Robo-Dexo suit and bring her back.
Old Man Dexter (Episode 3)
Air date: 1996-03-24
Runtime: 7 min
Overview: Dexter wants to use his Hydro-Cosmetic Accelerator to age himself enough so he could watch late night television without his parents objecting.
Dumb Like Dee Dee (Episode 4)
Air date: 1996-04-14
Runtime: 7 min
Overview: After working himself too hard, Dexter's brain snaps.
Ego Trip (Episode 5) 10.0
Air date: 1999-12-10
Runtime: 60 min
Overview: When Dexter is attacked by Robots hunting "The one who saved the future", he becomes fascinated by the possibility of what he will be in several years time, taking the Time Machine. Dexter arrives in the future where he finds many things have changed...and that his greatest invention holds the key to total tranquility around the world, but in the hands of evil, also holds the key to total domination of the world
Rude Removal (Episode 6)
Air date: 2013-01-22
Runtime: 7 min
Overview: Dexter invents the Rude Removal System, a machine to remove the rudeness from Dee Dee.
What's His Name? (Episode 7)
Air date: 2000-06-30
Runtime: 7 min
Secret Formula (Episode 8)
Air date: 2002-08-23
Runtime: 7 min
Back to the Lab (Episode 9)
Air date: 2002-08-16
Runtime: 7 min