Wind Waker: A New Disturbance
Helmaroc King first appears in the Wind Waker: A New Disturbance story scenario. It first appears under the name Great Bird and its part of the Great Bird's Forces Rogue Faction (of which it is the only member). The Monster Forces lead by Boss Blin manage to drive it from its roost in Forsaken Fortress, causing it to attack the Hyrulean Forces lead by Link and Tetra in Windfall. Tetra and Link can force it to retreat by attacking it, which will cause it to fly off. Helmaroc King is basically a distraction in the scenario and cannot be defeated as the main focus is to defeat Boss Blin and the Monster Forces.
After the defeat of Boss Blin and the Monster Forces, Link spots Helmaroc King in the sky and notices that he is carrying Tetra in its talons. Link rushes after Helmaroc King to save Tetra.
Wind Waker: The Search for Cia
In Wind Waker: The Search for Cia, Helmaroc King decides to roost in the Arbiter's Grounds located in Gerudo Desert. While it was resting, Tetra manages to sneak away and seeks the aid of Lana and the Hyrulean Forces, who had entered the desert to close the Gate of Souls that had opened up there. Eventually, Helmaroc King awoke and tried to recapture Tetra, who calls upon Lana and the recently arrived Link to save her. They manage to destroy Helmaroc King's Mask, forcing it to retreat momentarily. However the Great Bird soon returns, only to be killed by the combined might of Lana, Link, and Tetra.
Helmaroc King fights primarily using its beak and talons. It can also wipe up whirlwinds with its wings and fire its feathers as projectiles. Like in The Wind Waker, Helmaroc King's beak occasionally gets stuck in the ground when it peaks at its opponent, making it vulnerable to the Hammer/Upgraded Hammer. Hitting it with the hammer while it is vulnerable will put Helmaroc King into a downed state causing its Weak Point gauge to appear, allowing the player to perform a Weak Point Smash. It can also be put into a downed state by hitting it with a Focus Spirit Attack.
However, it should be noted that Helmaroc King may occasionally fly off (this usually occurs when it is fought in the story), then reappear in another location.