Agent M is a monkey agent of the O.W.C.A. who first appeared on the Phineas and Ferb Musical Cliptastic Countdown episode. In this episode, he was typing the cue cards for the show on a typewriter. This is a play on the saying: If you had an infinite number of monkeys, and an infinite number of typewriters, they would eventually write the works of Shakespeare.
- Despite that he's a monkey, the absence a tail technically makes him a chimpanzee, which classifies him as an ape and not a monkey, however, this may have been an animation error since he had been shown with a tail in all other episodes.
- In "Where's Perry? (Part Two)", Perry recruited another monkey agent while in Africa.
- Carl said Agent M spilled a latte on an antique couch. ("Doofapus")
- "Phineas and Ferb Musical Cliptastic Countdown" (First appearance)
- Phineas and Ferb the Movie: Across the 2nd Dimension (Cameo)
- "Agent Doof"
- "Doofapus" (Mentioned only)
- "Where's Perry? (Part Two)" (another monkey agent in Africa)
- "Backyard Hodge Podge"
- "La Candace-Cabra"
- "Phineas and Ferb Save Summer"
- Where's My Perry? (Agent File)