lavitzlover said: lol some kind of cow monster in the back ground..
That's the Minotaur Guard of Impel Down.
As for why they allowed Crocodile to keep his hook... it may be that if he had the hook prior to eating the Suna Suna no Mi (which is likely since that fruit is a Logia class and makes him all but invincible to most kinds of harm save Haki based attacks), then it is entirely plausible that the hook or at least the base of the Hook is actually now part of his body and cannot be removed, in much the same way that a Devil Fruit User's clothing is affected when they use their Devil Fruit Powers (which explains why Ace's clothes don't disintegrate when he catches on fire, or why Luffy's shirt buttons don't pop off when he inflates).
