Biography
Jeff "Swampy" Marsh (born December 9, 1960) is an American animator, writer, director, producer, and voice actor associated with several animated television series, most notably as an executive producer and the voice of Major Monogram for Disney's animated series Phineas and Ferb and Milo Murphy's Law, both of which he co-created with Dan Povenmire. Marsh was born in Santa Monica, California, where he grew up with a heavily blended family dynamic. Marsh has been and continues to be a driving force behind several animation projects, working for over six seasons on the animated television series The Simpsons. Marsh continued to work on other animated television series, including King of the Hill and Rocko's Modern Life, before moving to England in 1996.
Known For

O.W.C.A. Files
Major Monogram / Additional Voices (voice)

Phineas and Ferb The Movi...
Major Francis Monogram / Monogram-2 (voice)

Spiked
(voice)

Phineas and Ferb the Movi...
Major Monogram (voice)

Phineas and Ferb: Mission...
Francis Major Monogram / Gordon Gutsofanemu / Additional Voices

Phineas and Ferb: Star Wa...
Major Hologram / Imperial Officer Jeff / Additional Voices

Phineas and Ferb Christma...
Major Monogram (voice)

I Know That Voice
Self

TV's Funniest Animated St...
Self

Phineas and Ferb: Night o...
Major Francis Monogram (voice)