The Amazing Peacock Mantis Shrimp

I saw this guy (Odontodactylus Scyllarus) in an aquarium in PengHu, Taiwan. Looking like some kind of alien dragon thing, he has such a powerful punch, similar to a bullet, they had to remove part of his front arms for fear of him punching through the plexiglass. Not the kind of thing you want to meet in a dark alley, or when snorkelling.