The Garfield Show Tome 5
Fido Food Feline

Looking for super-heroic action and adventure ? Well, Garfield does actually turn into the caped avenger to find the thief who stole a comicbook worth a million dollars ! But mostly he leaves the heavy lifting to squeak's friend Biff-the super-strong buff mouse ! Oh, and garfield does have a non-secret identity crisis when he accidentally eats dog food and thinks he's turned into a dog. So, this may not be the graphic novel for super-thrills.
It's just the same old Garfield, just the way you love him - fat and as lazy as ever !