Thoroughly Mixed-Up Mouse is an episode from the seventh season of Garfield and Friends.
When Floyd's friend Irwin wants to be a cat, Garfield shows him how it is done. Irwin quickly finds out that being a cat is harder than it seems.
Floyd and Irwin are walking through town with Irwin commenting on how great cats are. Heading toward a house, Floyd climbs up the drainpipe and into the house to get something to eat. Once inside, he says that even though Irwin is a good friend, he talks about cats all the time right when he is spotted and getting chased by a house cat. The chase then leads to a street, where at the same time Garfield is getting chased by a dog. The two cross paths causing their chasers to crash into each other giving them a chance to escape.
Back at Garfield's home, Garfield goes to the kitchen to get something for Floyd while Irwin admires how Garfield is. With curiosity getting the better of him, Floyd asks him why does he admire cats so much and Irwin replies he wants to be one. Despite his objections and even shows a host on TV saying they can be anything they want, Floyd says he cannot change his species. Coming back with a cracker, Garfield hears about Irwin wanting to be a cat. He asks him if he can eat and sleep which Irwin says yes and he concludes he has all the traits. As Garfield takes a nap, Floyd wonders if this is a good idea. Garfield assures that since all cats eat and sleep, Irwin should not have a problem.
Irwin takes no time in acting like a cat; he quickly finds out it is harder than it seems. He comes across a carton of cat food with ingredients that make him gag. Odie then comes along and slurps him though Irwin runs away thinking he is going to eat him, confusing the dog. He then realizes cats chase mice which leads to him chasing Floyd out of the house.
Eventually the chase leads to an alley of cats which causes Floyd to hide. Irwin tries to interact with the cats, leading to the cats in turn giving him a beating. Watching this, Floyd runs back into the house to get Garfield to fix this as Irwin recovers wondering if cats are hostile to each other.
Despite the hardships, Irwin continues to be a cat and Garfield sees what happened. To straighten things out, Garfield says to Irwin that he always wanted to be a dog and Irwin accepts to be one. This turns out to be a mistake as dogs chase cats, leading Garfield to chase Irwin.
The chase ensures through the neighborhood where Jon (who recently bought groceries) sees the chase. He then checks the ingredients in the cat food to see what is causing the sudden change in behavior. Eventually the chase ends in another alley and now cornered, Irwin finally cracks. He denounces Garfield as a dog and himself as a cat and declares he is proud to be a mouse. Garfield is relieved that its over and Floyd congratulates him for saving Irwin's life. He then asks if he could be on the show more to which Garfield says not to push his luck.
- The host Irwin displays on the TV is a spoof of Fred Rogers and Mr. Roger's Neighborhood.