In Sumerian myth, Anzu was a large bird (eagle or vulture) who lived in the realm of the gods.
Demon Descriptions: Bird
Below you will find a list of demons that can take the form of a bird.
Once with the order of angels, and currently, high president of hell, Caym/Camio commands 30 legions.
The bird, Garuda, usually serves as a mount for the God Vishnu.
Phenex, the 37th spirit, is a great Marquis who appears like the bird Phoenix.
In Mayan mythology, Vucub Caquix, Seven Macaw, was a large bird that dwelled on the surface of the world after the flood.