Dexter's Laboratory (commonly abbreviated as Dexter's Lab) is an American animated television series created by Genndy Tartakovsky for Cartoon Network. It follows Dexter, a boy-genius and inventor with a hidden laboratory in his room, which he keeps secret from his parents. He is at constant odds with his older sister Dee Dee, who always gains access to Dexter's lab and inadvertently foils his experiments. Dexter has a bitter rivalry with Mandark, a fellow boy-genius who is his neighbor and classmate. The segments featured superhero-based charactersMonkey, Dexter's pet lab-monkey/superhero, and the Justice Friends, a trio of superheroes who share an apartmentand are prominently featured only in the first two seasons. Tartakovsky pitched the series to Fred Seibert's first animated shorts showcase What a Cartoon! at Hanna-Barbera, basing it on student films Tartakovsky produced at the California Institute of the Arts. Four pilots aired on Cartoon Network and TNT from 1995 to 1996. Viewer approval ratings led to a half-hour series, which consisted of two seasons totaling 52 episodes, airing from April 27, 1996, to June 15, 1998. On December 10, 1999, a television film titled Dexter's Laboratory: Ego Trip aired as the intended series finaleTartakovsky himself began to work on Samurai Jack.