Curse of the Were-Dog is the twenty-first episode (in the U.S.) and the fifteenth (in Europe) from the first season of The Garfield Show.
One night, each time the full moon comes out, Odie turns into a huge out-of-control monster.
Jon is busy making lasagna for Liz's birthday. When Odie shows up hoping to play, Jon sends him out with a bone. Odie becomes cautious when he hears the sound of growling, only to run into Rottweiler, who makes Odie give him the bone by intimidation. Garfield eventually smells the lasagna, which lures him away from the TV. Just as Garfield is about to eat it, Jon warns him not to do so. Garfield reluctantly complies after Jon threatens not to feed him. Meanwhile, the TV features a news segment about a rare star alignment, with Professor Harlow Franz claiming that the alignment could have an effect on dogs with almost no intelligence.
Odie returns to the kitchen, sad about losing the bone, as Jon decides to go to bed. Jon figures that Garfield was able to forget about the lasagna, while Garfield struggles to keep himself from eating it. When moonlight shines into the living room, Odie transforms into a giant beast and goes into the kitchen, where he devours the lasagna. When the clouds block the moonlight, Odie goes back to his regular self. Jon wakes up from the commotion and comes down to find the lasagna gone. Assuming that Garfield was responsible, he confronts the fat cat and tells him he’ll never feed him again. Garfield is shocked, since he can’t even remember eating the lasagna.
When the moonlight returns, Odie transforms again, and goes on to mess up the living room. Jon, feeling he was too rough on Garfield, decides to talk to Garfield again. When the moonlight disappears again, Odie returns to normal. After Jon turns on the living room lights, he sees the living room trashed, and once again blames Garfield for it; he is also unable to see how Odie could have done it.
Odie sadly heads outside, where he encounters Rottweiler again. Just as Rottweiler is about to get rough on him for not bringing biscuits, Odie once again transforms and throws the other dog all the way into space. When Jon finds out about the alignment and its potential effects, he realizes how Odie, and not Garfield, could be responsible for the lasagna and events. The two then find Odie (who is back to normal), and take him to the professor.
By the time Odie is checked, the professor notes that the alignment is over and therefore no longer a problem. The professor then notes that there is now another alignment occurring, which can affect cats that eat large amounts of Italian food. Garfield then becomes a giant beast, causing the other three to flee. Garfield then wonders if the all-night pizza place is open. Meanwhile, Rottweiler, in space, encounters Nimbus.