Garfield is visited by his angelic good side and devilish bad side, battling over who gets to control his actions.
One morning in the kitchen while Garfield is enjoying his morning coffee, Jon comes in and tells him not to annoy the mailman today as he's expecting a very important package. Garfield checks his calendar and sees that today's the day he annoys the garbage man and decides to take a nap.
However Garfield's bad side suddenly appears and urges him to do rotten things like kicking Odie off the table. At the same time his good side comes in and tries to prevent him from doing it. The bad side however proves to be more determined as he stuffs the good side into a miniature cannon and ejects him out of the house. After a bit of persuasion and some hesitation, Garfield eventually kicks Odie off the table. Jon however saw that and berates him for doing that and then goes out to mow the lawn.
Hearing this the bad side gets another idea, while the good side comes back into the house and tries to stop anymore trouble. The bad side doesn't want any intervention and in doing so, stuffs the good side into a rocket and ejects him out of the house. Once ejected, the bad side tells Garfield his plan and while he says it won't be nice, the bad side says it's not supposed to be nice.
Out in the backyard while Jon isn't looking, Garfield sneaks by and tampers with the power mower. Heading back, Jon comments that Garfield is a behaved cat but gets into mischief now and then. Hiding in the bushes, Garfield and his bad side watch as Jon turns on the power mower which goes out of control. Garfield watches in shock while his bad side laughs at Jon's expense as he crashes into the garage. Recovering, Jon confronts Garfield if he tampered with the mower to which Garfield replies no. Once Jon leaves, Garfield tells his bad side that he made him into a liar though his bad side says all liars eventually become weathermen.
Finally his bad side sees Herman Post and tells him to harass him. Right then his good side attempts to stop him but the bad side ties him up before he says anything and orders Garfield to harass the mailman. Jumping into his cart, Garfield finds a package meant for Jon. But before he could see what's in it, he accidentally drops the package on the cart's brake causing it to go down the neighborhood. After a skirmish and a crash, Herman Post recovers his cart and give Jon his package and Garfield.
Back in the house, Jon complains that he's given everything Garfield wants but something still gets to him and does all the tricks and can't figure out what it is. However Jon admits he's still his cat and gives him his personal mug, which is what was inside the package all along. Seeing this, his Good Side says he should be thankful for the gift, though his bad side says the mug was a steal. Garfield though hopes nothing happens to the mug but due to his harassment with the mailman the mug cracks and shatters into pieces. Infuriated, Garfield and his good side chase the bad side through the house and outside, since the bad side's deeds got the mug broken in the first place.
As Jon watches Garfield running outside (as he can't see Garfield's Good Side and Bad Side) Jon admits he'll never understand Garfield. Just then Jon's Good and Bad sides emerge as they both decide what should Jon do with Garfield.
- Woman (voiced by Julie Payne)
- Jon Arbuckle's Bad Side (voiced by Thom Huge)
- Jon Arbuckle's Good Side (voiced by Thom Huge)