Helmaroc King

In The Wind Waker
The Helmaroc King is a monstrous bird that was manipulated by the evil Ganon. The bird was designed to do dirty deeds for Ganon, one of which was to soar the skies and search the many islands for young girls with pointy ears(A Hylian trait) and then kidnap them. The very same bird is responsible for the kidnapping of Link's sister, Aryll. This bird wears a protective stone mask which requires a heavy weapon to destroy. The bird has a habit of getting it's beak stuck in the ground, making it open to attack. It also has trouble stopping itself from slamming into the towers around it's battle arena, the pinnacle of the Forsaken Fortress. The Helmaroc king has three attacks:

1. Creating a gust with his wings, trying to blow you into the spikes on the wall. 2. Diving down to scrap his feets over the ground. 3. Landing, walking towards you and pecking with his beak, which will be stuck in the ground when he does this. This is the moment you have to attack him. Swing your Skull Hammer and hit the Helmaroc King with your hammer. After a couple of times, his mask will fall of. Repeat this steps to defeat him.

In Four Swords Adventures
In Four Swords Adventures, this boss was designed to stop you from entering the Tower of Flames. This monstrous bird would swoop down up Link twice, then drop rocks upon him and his clones, then repeat the process. To defeat this boss, Link would have to daze the bird with bombs to help him destroy the mask. After the mask was destroyed, then he could finish the job easily.

Twilight Princess?
The Helmaroc King might be related to Argorok in TP, they both have similar names and looks, maybe the Helmaroc King is a more advance version of Argorok.