Agent X is the eighth episode (in the U.S.) and tenth (in Europe) from the first season of The Garfield Show.
A new cat, claiming to be a secret agent, steals Garfield's friends by telling fake stories.
The episode begins with Garfield telling a story to Arlene and Nermal on how he was at an all-you-can-eat restaurant for three weeks, causing the entire building to go out of business and become a discount shoe store. When Nermal threatens to not leave until he tells him another story, Garfield throws Nermal into the lid of a trashcan.
Inside the trashcan is a cat, calling himself "Agent X", who claims he's on a mission of saving all of mankind. He is hiding from a man, who is a part of an organization involved in the evil plot. Nermal then hides X inside Jon's toolshed. While inside, he begins telling stories of his exploits all over the world (and eating food meant for Garfield). Garfield grows jealous of X and leaves with Squeak in order to find the guy looking for him.
Eventually, Garfield finds the man looking for X, who is actually a detective looking for Fluffykins, a household cat of an old woman. Garfeld realizes from the old woman's pictures that X is Fluffykins, thus he is just a household cat on the run and a fraud. Garfield comes up with a plan to get him out and restore his popularity.
Garfield then returns to his friends and tells them, that X is a fake. Nobody believes him, but then Garfield points out that "X's" enemy, evil spy Mr. Tig, is here (who is actually Squeak). Eventually, Fluffykin runs away into a tree, and makes a deal with Garfield to return to his owner and Garfield won't reveal he's a fake. Garfield gains his popularity back and everything is back to normal.