Jeffrey “Jeff/Swampy” Marsh is a director, writer, producer, animator, and voice actor. Co-Creator of Phineas and Ferb with Dan Povenmire, he has directed, written, and acted in this Disney Channel Original Series. In Phineas and Ferb, he portrays the voice of Major Francis Monogram, the commander of Perry the Platypus. From the show’s inception, Swampy has been one of the main songwriters for the series, along with Dan Povenmire and Martin Olson. Before working for Disney, he was one of the writers of the Nickelodeon program Rocko’s Modern Life.
Nominated along with Dan Povenmire for two Emmy awards: “Outstanding Original Main Title Theme Music” and “Outstanding Original Music and Lyrics” (for “Ain’t Got Rhythm”)
Nominated along with executive producer Dan Povenmire, director Zac Moncrief, et al., for the Emmy Award for “Outstanding Short-Formed Animation Program” for Phineas and Ferb (episode: “The Monster of Phineas-n-Ferbenstein”)
He got the nickname "Swampy" while attending college in England, in reference to his surname. He added the nickname as an intertitle in his credited and preferred name, Jeff "Swampy" Marsh, as a means of making it longer than most others' names, at fifteen letters.