Captain's Hat

The Captain's Hat is a skull-like hat obtained in Majora's Mask. The hat is designed to look like Captain Keeta, and as such, displays itself as a symbol of authority. Anyone who wears it is immediately mistaken for Captain Keeta, and this will cause Stalchildren to not attack Link, and will in fact allow him to communicate with them and command them to do his bidding (exactly what happens is dependent on the current day). If Link wears the mask right before he battle King Igos, he will think that Link is Captain Keeta. The game will go into a short cut scene, before returning to the battle.

Obtaining the Mask
Obtaining the mask is simple. Simply defeat Captain Keeta in Ikana. He will submit to your power, and will show you a treasure chest containing the Captain's Hat. Simply climb up to the archway the chest is resting on, jump the gap, and claim your prize. Or for a more simpler way, simply use the Hookshot.