Norse
Tyr
The Norse god of oaths and fair dealing, who lost a hand keeping a promise to a wolf.
Tyr is an old Norse god, linked with war, justice and oaths. In the best-known tale, the gods wanted to bind the wolf Fenrir with a magic ribbon. Fenrir agreed only if one god put a hand in his mouth as a promise, and Tyr was the one brave enough. When the ribbon held, Fenrir bit the hand off.
In our stories the tale is softened and changed: the ribbon is never used, and the promise is mended.