Odie digs up some bones and finds that they are from the very rare Brachiosaurus. Garfield tries to sell them to the local museum, but the museum curator instead wants to compulsory purchase and demolish Jon's house to search for more dinosaur bones.

Squeak and his family move in to Jon's house while Jon and Odie are out. Garfield allows Squeak's family to remain in the house on the condition that they be his servants. Jon comes back and Garfield has to remove Squeak and his family before Jon called Rat-Tator Pest, who's hefty bill would have meant that Jon would not be able to afford lasagna for years.

Garfield goes to visit Jon's little brother Doc Boy. But with no TV and no pizza, Garfield shows the farm animals how to live life his way.

Odie runs away from home, sick of Garfield's cruelty towards him, but the new house he runs off to is the residence of a boy with the personality of a mad scientist named Nathan, who plans to use his new invention to transform Odie into a cockroach. Now it is up to Garfield to save Odie.