Loki

Loki once made a bet with the dwarf Brokkr, claiming that his brother Sindri couldn't forge items as magnificent as those made by the sons of Ivaldi. If the dwarves succeeded, Loki would owe them his head. Sindri and Brokkr forged three incredible treasures: Gullinbursti, a golden boar; Draupnir, a magical gold ring; and Mjolnir, Thor’s mighty hammer. The gods judged that the dwarves had indeed won the wager. However, when Brokkr came to collect Loki’s head, the trickster god found a loophole—he had promised his head, but not his neck. Since they couldn’t cut off his head without harming his neck, Brokkr settled for sewing Loki’s mouth shut as punishment for his deception.