First Dog on the Moon – or Mr Onthemoon, if you want to be formal – is Australia's only Walkley award-winning marsupial-based cartoonist, and has done all sorts of things. His instantly recognisable cartoons for The Guardian are shared far and wide, but exactly who is the dog behind the page?  Join fellow satirist Mark Humphries on a quest into the wild heart of anarcho-marsupialist politics.