Calvin stands next to a snowman lying on the ground. Calvin says that by the power invested in him by the mighty and awful snow demons, he commands the snowman to come to life. He tells the snowman to live! The snowman rises up. Calvin runs off, with the snowman in hot pursuit.

Calvin runs inside, gasping for air. Calvin tells Mom he built the snowman, but then he brought it to life. Now, the snowman is after Calvin. Calvin tells Mom to look out the window. Mom looks and sees the snowman on the front step. She asks how they'll get out the door. Horrified, Calvin says he's looking in and now knows where he lives.

Calvin and Hobbes hide behind a tree. Calvin didn't know the snowman he brought to life would be evil. He knows they have to get rid of it. Hobbes suggests luring him inside so he'd melt. Calvin rejects that idea. It would take hours, it might kill Mom, and if it didn't, Mom would have a fit about the water on the floor. Hobbes asks how they finally killed "Frosty". Calvin wishes he'd watched that show. He suggests maybe they stabbed him with an icicle.

Hiding behind a tree, Calvin and Hobbes attack the snowman with snowballs. They stick to the snowman. That gives the snowman an idea. He starts packing more snow onto himself, making himself bigger.

The snowman packs more snow onto himself. It makes a big snowball and puts rocks and sticks onto it. The snowman has given himself another head. Hobbes says anytime the sun wants to come out is alright with him. Calvin notices the snowman has added another arm. It's turned itself into a deranged mutant killer monster snow goon.

The snow goon goes to the front yard. Calvin and Hobbes cut around the house to build a snow fort. Calvin doesn't know what the snow goon is going to do, but he knows they're going to need protection. Dad tells Calvin the snowman out front is hideous. He asks why Calvin can't build a normal one. Calvin replies that he tried.

Calvin and Hobbes are building their snow fort. The snow goon makes another snow goon. Calvin, in their snow fort, says they're safe now. Hobbes wonders why they haven't seen him for awhile.

Susie comments on Calvin's snow fort. Calvin tells her the walls are two feet thick and they have fifty snowballs. Susie wonders who he's fighting. Calvin tells her there's a snow goon running loose. Susie asks what a snow goon is. Calvin explains it's like a snowman, but it's an evil, grotesque, demented monster. She asks if that's what all those ugly things in the yard are. Calvin asks what she means by "all those".

There's a new snow goon, but it's not one Calvin made. He says the original snow goon must be making his own. Calvin fears he's making a snow goon army. He speculates how many there would be if the original made a hundred snow goons, then each of them makes their own goons. Calvin thinks that would be cool, if they weren't out to kill him. Hobbes suggests making tracks for Florida.

Mom yells for Calvin to come inside, it's late. Calvin replies that he has to stay to kill snow goons. Mom says he can kill them after school tomorrow. Calvin warns there will be more of them then. Mom tells Calvin to come in. As he heads to the house, Calvin says that Moms and reason are like oil and water.

In bed, Calvin asks Hobbes if he sees any snow goons outside. He says they're still making more. There are about fifteen now. Calvin doesn't think he'll even make it to the bus stop tomorrow. He is sure the snow goons will catch him. Mom kisses Calvin good night. Calvin asks her if he can bring an ax to school tomorrow....for show and tell.

At night, Calvin looks out his window to see the snow goons aren't moving. They're asleep. Calvin thinks this will be their best chance to bump them off. Hobbes says they can't go out now, it's 10:00 at night. Calvin says Mom and Dad will still be up. They'll have to wait at least an hour.

Calvin and Hobbes quietly come down the stairs, saying "Shh" to each other. They get dressed to go outside, saying "Shh" to each other. They leave the house, saying "Shh" to each other. Mom and Dad are startled awake by Calvin yelling for the snow goon to die.

Calvin is spraying water over the snow goons. He says he'll freeze them where they snooze. He walks through the yard spraying water all over. He covers all the snow goons, then sprays some more water around to be sure everything's frozen. Hobbes notices Mom and Dad's light is on. He tells Calvin that he thinks Dad is coming. Calvin wonders if he should spray Dad, also.

Mom and Dad get out of bed. Mom sees Calvin outside with the garden hose. Dad runs outside yelling for Calvin to come inside. He slips on the ice created by Calvin's watering and slides across the yard. Calvin runs off with Hobbes while being chased by Dad, who is covered with snow. Calvin yells that Dad is a snow goon, too.

Dad carries Calvin into the house. Calvin says he can explain. He tells Mom that he had to freeze the snow goons or they would have gotten him. Dad tells Calvin it's after midnight. He says they'll discuss it very thoroughly tomorrow. He sends Calvin to bed. Wide-eyed, Calvin tells Hobbes he's not going to get any sleep now.

Calvin explains to Mom and Dad how the snow goons were building an army. He asks if they see. He explains he had to freeze them while they were sleeping. He asks if they see. He says it all makes sense. He asks if they see. Mom and Dad just look at Calvin. Sitting on his bed, Calvin tells Hobbes they never see.

As the snow goons melt, Calvin tells Hobbes there's a moral to all this. He says "snow goons are bad news". Hobbes says that lesson certainly ought to be inapplicable elsewhere in life. Calvin tells him he likes maxims that don't encourage behavior modification.