Heimdall's Doom

Cannot be auctioned, traded, or bazaared, but can be delivered to a character on the same account.
Can be obtained as a random reward from the Gobbie Mystery Box Special Dial and similar sources.

In Norse mythology, Heimdallr is a god who possesses the resounding horn Gjallarhorn, owns the golden-maned horse Gulltoppr, has gold teeth, and is the son of Nine Mothers. Heimdallr is attested as possessing foreknowledge, keen eyesight and hearing, is described as "the whitest of the gods", and keeps watch for the onset of Ragnarök while drinking fine mead in his dwelling Himinbjörg, located where the burning rainbow bridge Bifröst meets heaven. Heimdallr is said to be the originator of social classes among humanity and once regained Freyja's treasured possession Brísingamen while doing battle in the shape of a seal with Loki. Heimdallr and Loki are foretold to kill one another during the events of Ragnarök.

In chapter 8 of the old Norse poem Skáldskaparmál, Heimdallr's head is known as his sword, though it is unclear why, and that, since the poem, "the head has been called Heimdall's doom: man's doom is an expression for sword." A more recent depiction shows a man's head engraved on the sword (Wikipedia).