 Perry the <unk> , also known as Agent P or simply Perry , is an anthropomorphic platypus from the animated series Phineas and Ferb . Perry was created by the series ' co @-@ founders , Dan Povenmire and Jeff " <unk> " Marsh . He first appeared along with the majority of the main cast in the pilot episode " <unk> . " Perry is featured as the star of the B @-@ plot for every episode of the series , alongside his nemesis Dr. Heinz Doofenshmirtz . A mostly silent character , his lone vocal characteristic ( a <unk> of Perry 's beak ) was provided by Dee Bradley Baker . 
