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Jeff 'Swampy' Marsh

Acting Born Dec 9, 1960 Santa Monica, California, USA 22 credits

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.

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Known for

Phineas and Ferb

as Francis Monogram (voice)
Film

Spiked

as Big Boss Croc / Exterminator (voice)

Full filmography

  • Phineas and Ferb (2007) as Francis Monogram (voice)
  • Milo Murphy's Law (2016) as Additional Voices (voice)
  • Phineas and Ferb The Movie: Across the 2nd Dimension (2011) as Major Francis Monogram / Monogram-2 (voice)
  • Agent P Under C (2026) as Major Monogram (voice)
  • Phineas and Ferb the Movie: Candace Against the Universe (2020) as Major Monogram (voice)
  • Phineas and Ferb: Mission Marvel (2013) as Francis Major Monogram / Gordon Gutsofanemu / Additional Voices
  • How Not to Draw (2022) as Major Monogram (voice)
  • I Know That Voice (2014) as Self
  • Aaagh! It's the Mr. Hell Show! (2001) as Josh (voice)
  • Bounty Hamster (2003) as (voice)
  • Phineas and Ferb: Star Wars (2014) as Major Hologram / Imperial Officer Jeff / Additional Voices
  • Phineas and Ferb Christmas Vacation! (2009) as Major Monogram (voice)
  • TV's Funniest Animated Stars: A Paley Center for Media Special (2015) as Self
  • Phineas and Ferb: Summer Belongs to You! (2010) as Major Francis Monogram / Additional Voices (voice)
  • Phineas and Ferb: Last Day of Summer (2015) as Major Monogram (voice)
  • Spiked (2025) as Big Boss Croc / Exterminator (voice)
  • O.W.C.A. Files (2015) as Major Monogram / Additional Voices (voice)
  • Phineas and Ferb: Night of the Living Pharmacists (2014) as Major Francis Monogram (voice)
  • Phineas and Ferb: The Perry Files - Animal Agents (2013) as Major Monogram (voice)
  • Phineas and Ferb Save Summer (2014) as Major Francis Monogram / Additional Voices (voice)
  • Untitled Phineas and Ferb Movie as Major Francis Monogram (voice)
  • Phineas and Ferb: The Daze of Summer (2012)