If you're looking for something more along eth lines of "draw on his face", he could always draw on his face with a grease pencil or charcoal? That wasn't invented with magic markers.

He could also do something to his hair/facial hair, maybe? Shave it or cut it in weird patterns?

If you want to split the difference between "mild prank" and "horrible death", there's the old 19th century American fun of slitting someone's nostrils and/or ears. Or branding? Or painting them with hot tar? All sorts of fun with mutilation can be had.