Cartoon markets: Writing the right gag

Like any job, you have to wear different "hats" as a cartoonist. Ordinarily, if asked to to a cartoon about Damien Hirst I would probably come up with something a bit sarcastic (as many cartoonists have done!). But when it's for a profile of said artist on the Artyfacts section of the Children's BBC website, something just plain silly is the order of the day.