The Mouse Agent is a small-sized agent has been seen in some episodes. In her first appearance, she's seen riding the elevator alongside the unnamed bear agent, unnamed crocodile agent, and others (" Isabella and the Temple of Sap "). She appeared again in " Phineas and Ferb Christmas Vacation! " dancing with the other agents. Her next appearance wouldn't be until Phineas and Ferb The Movie: Across the 2nd Dimension , where she's seen attacking Normbots alongside her fellow agents. She appeared again in " Agent Doof " and "
Phineas and Ferb Save Summer "
Her appearance is that of an ordinary mouse with a fedora.
Her boss in the
Agent M can team with the other Agents well, as it appears, in the 2nd Dimension movie. She is on good terms with Perry, and others, even her actual predators, so it can be assumed she does have friends in the Agency.