Because of their frivolous life, flies were used to signify sin throughout history. The capacity to command flies is the mark of the devil. Satan's lieutenant Beelzebub—the lord of the flies—is portrayed in a drawing from 1863 (reproduced in Fly) as a fierce fly-like creature with the skull and crossbones symbol on its wings. Satan himself, as well as many alleged witches and even Loki, the Nordic god of mischief, all change occasionally into flies.