Crayk

Crayk is the large, hermit crab-like boss in the Temple of Courage in Phantom Hourglass. When the battle starts, it turns invisible, but, on the top screen, the room is shown from Crayk's viewpoint (presumably because of the second half of the Fairy of Courage he is guarding). When the top screen shows him charging at Link, fire off an arrow, (on the top screen, you will see Link aiming at you) and he will withdraw into his shell. If Link fails to fire an arrow at him, Crayk will grab him, and you must move the stylus back and forth in order to break free. When in his shell, throw bombs at him. Link can also use his sword or arrows to break the purple orbs surrounding its shell (slashing is easier, but more risky). Once every purple orb has been destroyed, Crayk's shell will fall off, leaving its tail vulnerable. Fire arrows at him to stun him and then slice the tail. Once he is defeated, he will turn into Sand of Hours and Link will get a Heart Container and the second half of Ciela.

Trivia
Crayk has the Kokiri symbol on his shell repeated over several times.