Christmas Town

Mr. Hankey and his troubled family originally resided in the cheery area seen above. In The Stick of Truth, his living quarters were downgraded to a small house in the sewers.

Ginger Kid/Polly Prissypants Mission

We were shown one mission that started with Cartman lamenting the loss of his doll Polly Prissypants. He's convinced that the ginger kids stole her, and sends the new kid on a quest to retrieve her. After following a trail of doll hair, the player is taken into the woods where they encounter numerous red-headed children. 

This Thing

Apparently, this big dragon monster thing was gonna be a boss fight at one point.