In the very beginning of Andy Kaufman Plays Carnegie Hall (1979) he said that he always told his grandmother that someday he will perform live at Carnegie Hall and when he does he will give her the best seat in the house. Before the show started he introduced his grandmother and told that story. She then took a seat on the actual stage and didn’t say a word but watched the entire show. The show consisted of his usual routines, Elvis impersonation, wrestling, Tony Clifton, etc. as well as a number of special guests. After the 2 hour show was over Andy began to thank all of his guests for performing and then he thanked his grandmother, Robin Williams. Robin Williams sat on the stage dressed as an old lady for the entire performance and not a single person at Carnegie Hall knew that. It was absolutely amazing. RIP Robin Wiliams. I hope that this is another one of Andy’s pranks. 🙁