Oocca

The Oocca are a race living in the sky. Their appearance is similar to that of yellow Cuccos with a pale human-like heads. Their children appear as small, pale, human-like heads with wings. They were first introduced in The Legend of Zelda: Twilight Princess.

Location
The Oocca live in the City in the Sky, but it's unclear whether they have always lived there. Unlike the Zoras who built Zora's Domain or the Hylians who built Hyrule Castle Town and Hyrule Castle, the Oocca don't seem to maintain the City in the Sky. Argorok contributed to the damage in the already ruined city, breaking bridges while many pillars had already collapsed beforehand. The city does not seem to have been designed for the Oocca, as Ooccoo was unable to return without the help of Link. Also notable is the fact that they have no arms or appendages with which they could use or manipulate tools, but show some possibility of telekinetic ability, as shown by multiple Oocca walking on walls.

Evolution
It is implied by Shad that it was the Oocca who created the Hylians. Contradicting this theory is the idea that the Hylians were created after the image of the goddesses. It may be that Shad has them confused with another race. It is also possible that the Goddesses created the Oocca, and then got the idea for the Hylians from them, creating them shortly afterward.

Another theory states that the Oocca were originally a highly evolved race that created many of the "divine" structures across Hyrule, but years of isolation made them devolve into the weak forms they now hold. This theory is supported by the fact that the Dominion Rod, an Oocca artifact, was stored inside the Temple of Time, which was always considered to be a sacred place to the goddesses. Similarly, the Clawshot also seems to be an Oocca artifact, since one is located in the City in the Sky. If this is true, the Oocca may have influenced the Zoras, as a second Clawshot located in the Zora Lakebed Temple. This could mean that the Oocca did not create the Hylian race, but instead were so highly advanced that the Hylians thought of them as gods, basing their mythology and culture off of Oocca leavings. So technically the Oocca could have "created" the Hylian race by giving it identity. It is known that the Oocca once had good contact with the Hyrulean Royal Family.

Culture
The Oocca have their own language, known as Sky Writing and some Oocca are able to speak Hylian (i.e. Ooccoo, the City in the Sky shopkeeper, and Ooccoo Jr.).

Trivia
Some fans speculate that the design for the Oocca came from M.C. Escher's painting, Another World. The painting features bird-like creatures walking on walls, and the Oocca are known to walk on walls themselves.