Aegir or Ægir (エギール, Ēgiru) is a demon in the series.
Aegir (Norse for Sea) is a sea jötunn (giant) associated with the ocean. He is listed as a giant in the Nafnaþulur, a subsection of the Prose Edda and some indetify him as the same as Hlér. According to Fundinn Noregr, he is a son of the giant Fornjótr, the king of "Gotlandi, Kænlandi and Finnlandi", and brother of Logi ("fire") and Kári ("wind").
His wife is Ran("Robber"), and they reside on Midgard at the bottom of the oceans. While most giants are at odds with gods, Aegir and Ran share a friendly relationship with them and are known for hosting elaborate parties for them. One of such parties is narrated in the Lokasenna, where Aegir provide an ale brewed in an enormous pot or cauldron provided by Thor and Tyr.
He and Ran have nine children: Bára, Blóðughadda, Bylgja, Dúfa, Hefring, Himinglæva, Hrönn, Kólga and Unnr who represent the spirits of the waves.