Possibly the Discworld's greatest clown up until the advent of Mavolio Bent.
Like Bent, Normo had no discernable sense of humour whatsoever in his own right. However, he had the real gift, or as he would have seen it, curse, of inducing uncontrollable laughter in others. People would go purple just watching him shave. At his last public performance, three people died of laughter, despite the fact that Normo had his back to the crowd and was only standing there on stage without participating. The then Patrician barred him from further public performance as he was so lethal, and he spent the rest of his short life in seclusion at the Fools' Guild.
Although treated with honour and great everence by the Fools, Normo was unable to stand it any longer and left a suicide note which plaintatively read "What is everyone laughing about?" - five words which had become his catchphrase in public performance. His suicide was such an impressive success that it took another seven people with him who fell about laughing rather than rescue him.
He is remembered to this day at the Guild with the Bouncy Normo Memorial Library.
A Roundworld comedian, who made his initial reputation with a mime show demonstrating how various people shaved in the morning, was Goon Show mainstay Sir Harry Secombe. First evolved in wartime as a result of watching his Army colleagues shaving, and realising there could be humour in it, Secombe performed this act to get out of the front line and get into an Army Entertainment troop (where he met fellow Goon Spike Milligan). He then used it in variety showbusiness after WW2 and still perfomed it occassionally up to his death in the late 1990's. Given Secombe's later contribution to showbiz, he can be forgiven for starting out as a mime artist...
Less amusingly, comedian Eric Morecambe and comic/magician Tommy Cooper both literally died on stage during their acts, both times from heart attacks. In both cases, as both were renowned physical comedians known for fooling about, onlookers initially responded to their deaths with laughter and applause, thinking they were faking it as part of the act...