Fluffykins (A.K.A. Agent X) is a grey runaway cat who claimed that he was a spy.
Fluffykins lived with an old woman before he ran away. To stay in hiding, Fluffykins lied to Nermal and said that he was a triple-A undercover secret agent named Agent X who was being hunted down by a man who was trying to destroy mankind. Nermal, Odie, Arlene, Harry and Squeak enjoyed Fluffykins' fake stories and even stole Garfield's food for him. Fluffykins told them fake stories about how he had saved Australia on a runaway train, had nearly being run off the road, seen the earth from outer space, and defeated ninjas. Arlene said he was the bravest cat she knew, not knowing he was lying. Garfield convinced Squeak to follow him inside the house, where a man in a detective's suit, hired by his owner gave Jon Arbuckle a picture of Fluffykins. After seeing the picture for themselves, Garfield and Squeak sneak over to the window of the house the man enters. After discovering the truth that Agent X was just a runaway house cat, Garfield decides to blow Fluffykins' cover and expose him as the fake he was, but Squeak says that the others might not believe him and only think he's jealous. However, Garfield decided that just in case they might not he will come up with a plan. Agent X said he pretends to be a house cat to use as his cover. However Squeak pretends to be a villain named Mr. Tig and challenges Fluffykins to a showdown. When he shows him his kung fu moves, Fluffykins, scared to be hurt, flees and climbs a tree and admits was pretending to be a secret agent. Garfield tells Fluffykins to go back to his owner while he took care of Squeak and he wouldn't tell the others that he lied to them about his stories. Fluffykins goes back saying he was going to quit acting like a secret agent.