Mímir 

Mímir or Mim is a figure in Norse mythology, renowned for his knowledge and wisdom, who is beheaded during the Æsir–Vanir War. Afterward, the god Odin carries around Mímir's head and it recites secret knowledge and counsel to him.

Mímir is attested in the Poetic Edda, compiled in the 13th century from earlier traditional sources, the Prose Edda, written in the 13th century by Snorri Sturluson of Iceland, and in euhemerized form as one of the Æsir in Heimskringla, also written by Snorri Sturluson in the 13th century. Mímir's name appears in the names of the well Mímisbrunnr, and the names Mímameiðr and Hoddmímis holt, which scholars generally consider to be names for Yggdrasil. Scholars have proposed that Bestla may be Mímir's sister, and therefore Mímir would be Odin's maternal uncle.