ERB recently posted George Carlin vs Richard Pryor.

Their season finale has other characters show up, and in this one, the list includes:

Bill Cosby
Joan Rivers
Robin Williams

Robin Williams is played by EpicLloyd, and makes several references to Williams' career, including the cake scene from Mrs. Doubtfire.

https://www.youtube.com/watch?v=7Bx7CFiWfU0

Cake is at the 3 minute mark.