Dr. Heinz Doofenshmirtz

Dr. Heinz Doofenshmirtz (or just Doofenshmirtz) is the main atagonist of the F Gang, and the leader of L.O.V.E.M.U.F.F.I.N. He was at first Perry's rival, until How the F Gang Started, in which he became the nemesis of the F Gang.

Personality
Goofy, eccentric, and overly-dramatic, Doofenshmirtz tends to babble and be rather random. Acting somewhat cliche in classic villain form, he'll commonly burst out in grand maniacal laughs and drawn out, somewhat overdone, monologues.

Trivia

 * It is possible Heinz originated from Germany due to his name and accent.