Giant Corpse Crab

The Skeleton Crab was a giant crustacean that inhabited the waters somewhere between the Land of Fire and the Land of Lightning.

Background
The Skeleton Crab attacked once and destroys a ship which a young sailor named Hishaku sailed on, killing a whole crew.

Abilities
The Skeleton Crab had razor sharp pincers, as well as an extremely hard shell. The barnacles on its shell could eat live humans. It had tentacle like appendages that could be used to grab its prey.

Adventures At Sea Arc
While the ship with Naruto, Aoba, Yamato and Might Guy on it was on route to the Land of Lightning from the Land of Fire, the crab attacked a seemingly abandoned ship that the shinobi had encountered out at sea taking Yamato captive. It was subsequently killed through the combined efforts of the shinobi and a ghost of Hishaku.