Cartman tells Philip, '..I'll make you eat your parents." This is a reference from the previous episode where Cartman made Scott eat his parents in the chili he made.
South Park: Bigger, Longer & Uncut was referenced twice in the episode also, once when Stan claims to have saved Terrance and Phillip's lives, and a second time when actual footage from the movie was shown during the screening of "Terrance and Phillip: Behind the Blow".