Sid the Spy-deris a new agent at the O.W.C.A. He appeared in Phineas and Ferb episode, Rookie of The Agency.
Major Monogram first introduced him to Agent P. Perry must train him to become an agent. But Sid seems very weak and can't fight anything. No matter how many lesson, he still fail over and over. Then he decided to quit. Then he's got captured by LOVEMUFFIN. Perry and other agents came to LOVEMUFFIN headquater and rescue him, but they all get trap by LOVEMUFFIN's members. However, he found a way to defeat the villains and free all the agents.
At the end, he became an agent and started fighting evil.