Need new monster of the sea!

We need a new monster of the sea and i have a good idea of what they can do. You know you can buy crab suit ? So why don't making a mega crab! that would be amazing. He would throw rock on the boat and he can hide himself in the sand. When you killed him he drop a key or a lot of random chest. If it's a key that he drop, that gonna lets the player going on an island where is a secret room and a lot of chest! Do whatever you want with is idea,that would just be UNBELIEVABLE!!thanks