I think it's supposed to be Pirates v. Ninjas, which is a whole phenomenon I don't really get http://en.wikipedia.org/wiki/Pirates_versus_Ninjas that they added zombies to. Looks like it's a zombie pirate fighting a zombie ninja. Not sure why ninjas would be riding dinosaurs at the end of the world, though...
Yeah, I didn't get it either.
Ninjas are kool! The next thing going round the writing world is Zombies V Unicorns after an anthology was released by Holly Black and Justine Larbalestier - I'm Gunning for the zombies!
The dinosaur makes that picture awesome, regardless of the inclusion of zombies, ninjas, pirates or any combination of the three.
That's a robot pirate fighting a dino riding ninja. It's loltastic!
It's a "who would win in a fight?" or "who is better?" argument between geeks. Some favor Pirates and some favor Ninjas. Another argument is Robots vs Zombies. The cartoonist has mixed all four types together "Pirate Robots vs. Ninja Zombies" in a geeky rendition on how the world will end. He threw a dinosaur in for good measure because what geek doesn't like dinosaurs? :p