Complex sentence: After being ignored by the prisoners for reading his new book and puts them on the shelf with the others and goes to sleep when all of the Cartmans, Stan, Kyle appear to sing to Charles "Hark the Herald Angel" sing during the credits.
Split into simpler sentences: After being ignored by the prisoners for reading his new book, he places his book on the shelf with the others and goes to sleep. Suddenly, Stan, Kyle, and all of the Cartmans appear to sing "Hark the Herald Angels Sing" to Charles during the credits.