Tentalus

Abysmal Leviathan Tentalus is the boss of the Sandship in Skyward Sword. The fight starts out in the control room beneath the ship. As you make your way back to the deck, Tentalus will send it's tentacles through the walls. Link must use a Skyward Strike to sever them. Upon reaching the ship deck, Tentalus will attempt to grab you with it's tentacles. These must be cut with a Skyward Strike. Tentalus will appear from the water. His single eye must be hit with an arrow at this time. Tentalus will fall. Link must run up to him, cut the tentacles surrounding his face, and attack the eye with his sword. After repeating twice more, Tentalus will begin to destroy the deck. A block will fall down and Link will have to climb it to reach the upper deck of the ship. Here, tentacles will begin to attack you by growing heads and charging. Use the same strategy as before to eventually defeat Tentalus.