

Doofenshmirtz appears in several merchandise pieces, particularly the book series, and the video game. Doofenshmirtz usually monologues and displays acts of cartoon-style physical violence towards his nemesis Perry, a skilled anthropomorphic platypus secret agent. Before becoming an evil scientist, Doofenshmirtz was a bratwurst vender until being put out of business by the hot dog industry. Throughout the series, Doofenshmirtz's flashbacks (of which are often told after Perry has been captured) explore his mentally abusive and lonely childhood growing up in the fictional village Gimmelshtump, Druelselstein. After most defeats, he shouts his catchphrase, "Curse you, Perry the Platypus!" His first invention as a child was simply called "Inator" which led to his modern contraptions usually ending with the suffix of the same name. Routinely bumbling, incompetent, and forgetful, Doofenshmirtz's plans–always involving various gadgets and inventions–have been thwarted by Perry the Platypus. Doofenshmirtz's main goal is to either destroy or rule the Tri-State Area which was suggested to him as a starting point before trying to take over the world. He is the father to teenage Vanessa Doofenshmirtz and is the head of his own company, Doofenshmirtz Evil Inc.

Heinz Doofenshmirtz (voiced by Dan Povenmire) is a mad scientist appearing in all but one episode's B-Plots thus far.
