Agent B is a bear secret agent working for the O.W.C.A.. When Agent Pinky was going to get his mission briefing on Professor Poofenplotz's hairspray scheme, Agent B appeared in an O.W.C.A. elevator along with five other agents ("Isabella and the Temple of Sap"). She also appeared at the O.W.C.A. Christmas party ("Phineas and Ferb Christmas Vacation!"). During the chaos at O.W.C.A. headquarters after Major Monogram was fired, she was shredding documents until instructed by Major-in-Charge Carl to "go into the woods and...see what's out there. ("Phineas and Ferb Save Summer")
- According to her secret file, she can get claustrophobic in elevators and isn't available for winter missions due to hibernation. (Where's My Perry?)
- Although she can attend Christmas parties as shown in "Phineas and Ferb Christmas Vacation!".
- "Isabella and the Temple of Sap" (First appearance)
- "Phineas and Ferb Christmas Vacation!" (Cameo)
- "Agent Doof" (Cameo)
- "La Candace-Cabra"
- "One Good Turn"
- "Phineas and Ferb Save Summer"
- "O.W.C.A. Files"
- Where's My Perry? (Agent File)