Near a Pokémon Center on a snow-covered seashore, Pikachu and its friends make a Snorlax out of snow. That night, they wake up to see the snow Snorlax outside their window, come to life! All the Pokémon sneak out to play with the Snorlax, who leads them to a fruit tree growing on a cliff. Snorlax wants the fruit, but the cliff collapses under Snorlax's weight. Fortunately, everyone lands on the Snorlax, which acts just like a sled—but it slides all the way out to the shore and right onto a drifting ice floe!
The drifting Pokémon are sucked into a whirlpool, but Snorlax freezes the whirlpool into an icy viewing platform where everyone can watch Water-type Pokémon swimming through the sea. The Pokémon try to sail away on a boat made of ice, but it falls apart and two Lapras come to the rescue. They bring them to a land of Snorlax snowmen, where the snow Snorlax can join its friends, then take Pikachu and the gang back home. Pikachu and its friends fall asleep and wake up the next morning, back in the Pokémon Center. Their snow Snorlax is still outside—as it all a dream, or just some wintertime magic?
On top of a hill behind a Pokémon Center, the Pokémon are building snowmen. They are all small, but Totodile has made a giant one. The other Pokémon decide to work on that, and Chikorita begins by marking out two dashes for the eyes. All the Pokémon work together so that, by that evening, they have made a very realistic snow Snorlax.
That night, while everyone is asleep, Pikachu wakes up and notices a white Snorlax peering through the window. Pikachu wakes the other Pokémon up, and they follow the Snorlax through the woods until they come to a tree on top of a cliff that overlooks the ocean. Snorlax points to an apple on the tree, which Chikorita picks with a Vine Whip. Everyone runs for it, but Snorlax eats it in one bite, slamming down on the weak cliff face, and making everyone plummet. Luckily, they fall on Snorlax, who slides into the ocean.
Stuck at sea, the Pokémon yell at Snorlax, who just falls asleep. Togepi points put the wondrous aurora lighting up the night sky, which they take a moment to enjoy. However, while they aren't watching the sea, they float into a whirlpool. Pikachu and Totodile try a Thunderbolt and a Water Gun, respectively, but the attacks prove useless. Just as they think all is lost, Snorlax wakes up and uses Blizzard, which freezes the water. They now effectively have their own aquarium, so they look at the passing Water Pokémon for a while.
When it is time to go, Totodile uses Water Gun, which Snorlax freezes. Bulbasaur and Chikorita then use their Razor Leaf attacks to carve the ice block into a boat. They use it to head back, but Geodude's bouncing around makes the boat break apart. They sink, but two Lapras come to their rescue, and take them to an island where there are many more snow Snorlax. As Snorlax waves, the Lapras take the rest of the Pokémon back to the Pokémon Center.
Everyone falls asleep, and when they wake up they are already back at the Center. Pikachu suddenly asks the Pokémon something. They all nod in assent, and they run up the hill to where they see their snow Snorlax sitting in the sun where they left it.