South Park: Season 3, Episode 16

3 - 16: Are You There God, It's Me Jesus

Cartman begins bleeding from his ass, thinks he's got his period, and is excited about finally entering puberty. Soon, the other boys begin waiting to have their "periods" too. Meanwhile, the new millennium is approaching and while people are going to see Jesus, they really want to see God. Jesus feels it's up to him to impress everyone, so he promises to host a fabulous New Year's event.