There's talk of a "Chewbacca defense" in the courtroom, we then see a picture of Chewbacca from this movie.
Excerpts from this TV episode are shown in this documentry/
Cartman's German dance is played over a scene of a ghoul
A narrator speaks of a character's heart growing bigger as it had been 3 sizes too small, just like in this tv special.
The bunny boiling scene is spoofed, but instead of a bunny, it's Mr. Twig, a puppet.