self-mutilation = a common theme in Scandinavian mythology. Typically, a deity will perform an act of self-mutilation in order to gain some kind of power. The following are important examples of this motif:

Balder - died in order to be reborn after Ragnarök.

Loki - destroyed his mouth to regain his speech.

Óðin - sacrificed an eye to gain otherworldly sight. He also hanged himself from Yggdrasil in order to gain the knowledge of nine runes.

Týr - lost his right hand so that Fenrir could be bound.