Jon won a Turkey, but it's alive and he refuses to kill it. Garfield wants a turkey dinner, but finds the bird a formidable adversary. The butcher refuses to take the live bird back, after some Garfield tricks even without compensation.
Odie is victim to a new dog badge law, and is taken to the pound. When Jon decides dinner won't be served until Odie's saved, Garfield goes to heroic lengths to rescue Odie.
Garfield's mouse friend brings dozens of relatives, who are willing to wait on the cat hand and foot but soon Jon demands their eviction or he'll hire an exterminator and pay for it with Garfied's lasagna budget.
An alien race resembling lasagna with limbs deem earth suitable for colonization provided they can handle the only apparently dangerous creature: the orange cat Garfield.
A fat cat claiming to be a heroic secret agent finds all other pets his captive audience and is served all treats, even Garfield's dinner. So his mouse friend is recruited to impersonate the foreign master spy to scare him.
Jon reluctantly accepts to mind Liz's aquarium during her short trip. Garfield was warned not to touch them, but can't resist. Alas, the feline glutton painfully experiences they all are dangerous.
When Jon misplaces Pookie, Nermal gets hold of the cuddly bear and uses it to blackmail Garfield into being nice for a whole day. When the torment becomes unbearable, Garfield resorts to inviting Jon's brat girl cousins.
Garfield impersonates Ultraman. Jealous of the generosity Nermal enjoys just for being cute, 'Ultraman' arranges to rescue the kitten and claims the lion share of edible rewards.
A TV test finds Garfield and Jon incompatible and splits them up. Now Garfield must deal with a horrible new playmate, while Jon is bored to death by a pet frog.
An alien scans Odie's brain and decides he needs help, and so, decides to switch Odie's brain with Garfield's. Now the cat must succumb to dog like desires and fun, while Odie's reckless actions endanger Garfield's body.
Hearing carolers get edible treats, Garfield tries it alone, but his feline falsetto arouses anger rather than generosity. Nermal and Odie are successful, so Garfield tries 'directing' them, or a mice choir.
The dog catcher fires his incompetent staff and replaces them with a robot, the T-3000. It ruthlessly targets almost all pets. Garfield and Odie team up with the fired dogcatchers to get them back instead of the horrible machine.
While Garfield watches TV, he's suddenly pulled into a wormhole and switches places with his counterpart in a parallel world, where humans are idle pets and felines carry all the responsibilities.
When Odie plays with a necklace Liz bought on Egyptian holiday, it transports him and Garfield to a Pharaonic culture in another dimension, where a feline cult plots to regain power over humanity.
Jon takes his pets along fishing. Dough balls prove terrible bait, but a young fish mistakes Odie's tongue for a worm and pulls him down to the sea bottom where an air bubble is provided. Garfield dives after Odie and saves the fish from a shark.
