South Park: Season 8, Episode 14

8 - 14: Woodland Critter Christmas

It's nearly Christmas, and Stan stumbles upon several little woodland critters in the forest. They want him to build a manger so a porcupine can give birth to their Savior, but he soon discovers that they actually worship Satan. Stan needs to stop the animal Antichrist from being born, and also stop Kyle from being its human host.