Robin Williams was 24 in The Complete Richard Pryor Roast when he played an uncredited character.
That was over 47 years ago in 1977.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
In 2014 he died aged 63, starring in 158 films in his career, 157 of those after The Complete Richard Pryor Roast was first released. If he were alive today he would be 72.
In The Complete Richard Pryor Roast, I think Robin Williams looks: