Crimson Desert: Iron Eagle

Game8's pet list and the Iron Eagle page agree this is a companion, not a saddle you fly. Hawkstone Ruins sits south of the City of Delesyia and is active at 05:00 in the game clock. If you arrive at noon, the page says the encounter is not there. Twenty Mercury is the food that pushes Trust to 100. After that, Sotdae of Bond is the item that completes the tame. Mercury is also the favorite food on the pet card.

People file this bird next to the wyvern because both have wings. The mount table does not include it. Phoenix is the other bird pet, and it wants a boss drop instead of a clock and a stack of Mercury.