Dexter's Laboratory is an American comic science fiction animated television show 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 as a secret from his parents. He is in a constant battle with his older sister Dee Dee, who always finds a way to get inside Dexter's lab and inadvertently foil his experiments. Dexter also engages in a bitter rivalry with a fellow boy-genius named Mandark, who is Dexter's neighbor and classmate. Prominently featured in the series' first two seasons are segments featuring superhero-based characters Monkey, Dexter's pet lab-monkey/superhero, and The Justice Friends, a trio of superheroes who share an apartment.