In Norse mythology, a character in this form breaks his promise to allow an earth oven to cook and gluttonously  consumes an (*) ox until Loki attacks him.
In Kwakiutl mythology, this animal was once asked to spot enemy canoes, so he traded attributes with a slug but refused  to trade back, dooming slugs to be slow. In Culhwch and Olwen, one of these animals directs Arthur's men to his ancient  enemy, the Salmon of Llyn Llyw, when asked about the whereabouts of the child Mabon. The early Sumerian king Etana  was granted a child for saving one of these animals from starvation after a serpent violated a truce negotiated by  Shamash. In Norse mythology, a character in this form breaks his promise to allow an earth oven to cook and gluttonously  consumes an (*) ox until Loki attacks him. That character, Thiazi, later snatches Idunn in this form, which was also used by Zeus  to abduct Ganymede. The Aztecs searched for this animal perched atop a cactus when relocating homelands. For 10 points, name  this giant bird that has a snake in its mouth on the flag of Mexico because of that myth.
In Kwakiutl mythology, this animal was once asked to spot enemy canoes, so he traded attributes with a slug but refused  to trade back, dooming slugs to be slow.
eagles [prompt on birds until mentioned]  2