South Park: Season 4, Episode 1

4 - 1: The Tooth Fairy's TATS 2000

When Cartman loses a tooth and finds money under his pillow, he and the boys come up with a plan to get rich off the Tooth Fairy. When they find out there is no Tooth Fairy, they formulate an even sneakier plan. Unfortunately, the tooth business is already well established by a mob-like group of kids. Kyle begins to question his parents' lies, and soon questions even his own reality.