In the outer reaches of the galaxy, a mother ship in the shape of a pressure cooker is home to some very strange creatures: space lasagna! Their ambition is to invade Planet Earth. Their plan to take over might fall through faster than they thought; after all, the one thing Garfield can never get enough of is lasagna.
Hunting birds is something Garfield gave up long ago. But when he finds a nest full of what look like abandoned eggs, Garfield puts his feline pride to one side and decides to hatch them. Harry, the stray, doesn't agree with this plan; he would love to put the newborn birds right on his dinner menu.
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 Mrs. Brubaker, the museum owner, instead wants to demolish Jon's house to search for more brachiosaurus bones. This is Esmeralda Brubaker and Hercules' first appearance.
Jon begins to notice that Garfield and Odie are more frequently causing messes around the house. Coincidentally, a salesman arrives at the house to sell Jon a highly technological cleaning robot. Jon accepts a trial of the robot before considering the purchase of one, but the robot becomes highly aggressive and violent when it is cleaning up after Garfield and Odie.
Nermal meets a cat so called "Agent X" who claims to be a Secret Agent, but in reality, he is just a runaway cat trying to impress the crowd. Garfield becomes jealous as Agent X tells everyone about his adventures of saving people. He soon discovers the true identity of Agent X (Fluffykins), and then turns around the tables in his way to get back his fame.
Are any pizzas better than Vito's? Of course not. But Jon thinks they could certainly find cheaper: they could go to Mama Meany, who is a nasty piece of work, more crook than cook, not very Mama at all. He has invented a machine: called the Pizzagrande 7000 which can pump out 10 pizzas per minute, all totally bland and completely inedible.
Jon trips over Odie, and the dish of lasagna he was carrying ends up all over Pooky, Garfield's favorite teddy bear. A quick spin in the washing machine gets him clean again, but now he has to hang outside on the washing line to dry. The next morning, Pooky is gone! Garfield is desperate, and looks for him everywhere.
A new law for dogs has just been introduced: any dog which goes out without a tag on its collar will be thrown into the pound without further ado. Odie gets caught by two guards and dragged off to the dog pound. Garfield therefore heads off to the pound to sneak in and rescue his faithful friend. But then who will get him out?
Tthere's a new TV game show which aims to find out if pets and their masters are really made for each other. Odie is confident that things will calm down once the show has proven Garfield and Jon make a good team. But his cunning plan quickly goes horribly wrong: the Compatriton machine, which never gets anything wrong, says they're incompatible. Garfield gets sent off to live with a boisterous kid called Jeremy, and Jon gets a new pet…. A frog!!
Garfield sends Odie to the end of a rainbow, promising that if he makes it before the rainbow disappears, he'll find a pot full of gold. Odie, who makes a good sleuth, finds it and brings it back to Garfield, much to the despair of its owner, a sad little leprechaun. If Garfield agrees to give the pot of gold back, all his dreams will come true.
Jon goes to visit his brother Doc Boy who lives on a farm. Garfield is a real city cat, it's no picnic for him! To make things worse, Doc Boy asks him to do some work: pile up some logs, wash down the windows, sweep up the leaves. Things really reach their low point when Garfield realizes there's no TV and no pizza.
Liz has just come back from a trip to Egypt and has brought an old mirror as a souvenir. But it's a magic mirror; one lick from Odie, and he and Garfield get sucked through a door into a parallel world! On the other side, the cats are waiting for their new Pharaoh to arrive, accompanied by his jackal.
Liz and Jon come home with a VIP guest : the cat Sir Leo, who is a star looking for a few days of R & R. He has always been famous, but dreams of a normal, peaceful life. Surprisingly he looks like Garfield, who jumps at the chance of replacing him for a while: he doesn't mind a taste of a star's life!
There's a house on fire and a young pup is crying for help: she thinks it's all over. But no – here comes Odie, the super dog! He wishes his dream was true. Then he could finally speak to the pretty stranger in his dreams. But when Garfield really gets into trouble, Odie puts his grudges aside and flies off to help him.
Eddie Gourmand is the judge for the Cutest Cat Of The Year award and decides for the new cute to be the opposite of cute, and the prize is six months in Greenland, so Garfield decides to make Nermal a mess in order to get some peace and quiet. Garfield wins the contest after getting messy from eating food left out for the audience.
Aunt Ivy stays at Jon's house after her power line is destroyed by a fallen tree branch. She eventually develops a fear of Jon's bunny slippers after watching a horror movie. The fear continues to mount when the blue moon outside causes the bunny slippers to come to life. This is Aunt Ivy's first appearance.
Jon sneezes every time he is near Garfield, and a doctor explains that he must get rid of Garfield, however when Garfield does something nice for Jon, he uncovers a shocking secret: he is allergic to goldenrod.
Garfield has to lose ten pounds, but Jon discovers he has been snacking between meals. Liz gives him a robot that will follow Garfield everywhere he goes to endure he sticks to his diet, but Garfield tricks Jon and pretends to board a ship bound for Tokyo, Japan.
Jon spends the day in Mr. Barker's new mansion to come up with a comic book idea. The only trouble is, the house is haunted by a ghost cat.
Dr. Bonkers creates a holographic mailman to prevent Herman from constantly being tormented by Garfield, but when Garfield eats a taco, from which sauce drips into the machine, causing the cyber mailman to deliver an early edition of the newspaper. This allowed Jon to buy the winning lottery ticket every day until the taco sauce causes the machine to blow up, destroying the post office lab. The explosion was foretold by Jon because of his early edition of the newspaper.
Garfield is looking forward to the holidays and all its joys. Arlene gives Garfield a reason to stop and remember the true meaning of the season, so Garfield decides to help some homeless Cats and Dogs by finding them homes. Part 2 is the first appearance of Jon's parents. This is the first double length (22 minute) episode.
Aliens from another planet plan to turn all the earth creatures into chickens.
Jon goes out on a date with Liz to Vito's Pizzeria and Garfield wants to go along, but Vito banned animals from entering the restaurant. So Garfield and Odie disguise themselves as children to get into Vito's, and Nermal and the other cat dress up as children. But Jon and Liz's date turns into disaster.
Jon goes out on a big date with Liz and orders Garfield a pizza for dinner from Vito's Pizzeria. Garfield races against Vito's new speedy delivery policy and torments him, but Jon eventually finds out, Vito then has Garfield pay off the hundreds of pizzas he ordered using a tape recorder. A variation of the Garfield and Friends cartoon "The Pizza Patrol".
Jon threatens Garfield to get rid of mice while a rat named Ratzo comes over.