Edit: on my Tumblr here ([link]
In adherence with my 'make something stupid and pointless every day' policy, it's the 'Avengers' poster. With Ankh-Morpork City Watch characters. Here's the original ([link]
Commander Sam Vimes is Ironhead (I was also considering Copperman or Stoneface).
Captain Carrot Ironfounderson is Captain Ankh-Morpork And Its Supporting Rural Environs.
Sergeant Detritus is The Incredible Splatter. It's like a Hulk, only splattier.
Sergeant Fred Colon is Wowhawk, expert marksman whose arrows seek out dragons' voonerables even - no especially - if it's a million-to-one shot.
Captain Angua Von Uberwold is Blonde Wolf. She spends a lot of her time pissed off, not least because somehow 'Blonde Wolf' fails mysteriously to sound as sexy and mysterious as 'Black Widow' or 'Scarlet Witch'.
Sergeant Cheery Littlebottom is (sorry) Phwoar.
They are brought together by the shadowy Havelock Vetinari, Agent of W.A.T.C.H. (probably) to protect the Disc from threats the like of which it has never - well, yet another cataclysmic threat, anyway.
Everything is mine, except the background elements which are stock. And the Tower of Art belongs to Jack Saxon ([link]