Mimir Earring

Cannot be auctioned, traded, bazaared, or delivered.
Cannot be obtained as a random reward from the Gobbie Mystery Box Special Dial and similar sources.

Mímir (Old Norse "The rememberer, the wise one") or Mimir 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. (Wikipedia)