Audumbla Sash

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

In Norse mythology, Auðumbla is a primeval cow. The primordial frost jötunn Ymir fed from her milk, and over the course of three days she licked away the salty rime rocks and revealed Búri, grandfather of the gods and brothers Odin, Vili and Vé. (Wikipedia)