Manny the Mongoose is a character who was mentioned in "Phineas and Ferb-Busters!" by Dr. Doofenshmirtz when he thought he had received his new "Nemesis Toy" in the mail. Nothing is known about him at this time.
- He appears in the Y.M.C.A. (Phineas and Ferb Remix).
- In Where's My Perry?, his agent brief says he is "small and nimble with good eyesight. He is highly alert and ideal for underground missions."
- He makes his first physical appearance on the show in Phineas and Ferb Save Summer.
- "Phineas and Ferb-Busters" (Mentioned only)
- "Phineas and Ferb Save Summer" (First appearance)
- "O.W.C.A. Files"
- Where's My Perry? (Agent File)