In Norse mythology, Geirrod was one of the Jotuns and father of Gjalp and Greip.
Loki was flying as a hawk one day and was captured by Geirrod. Geirrod, who hated Thor, demanded that Loki bring his enemy (without his magic belt and hammer) to Geirrod's castle. Loki agreed to lead Thor to the trap. On the way to Geirrod's, Loki and Thor stopped at the home of Grid, a giantess. She waited until Loki left the room, then told Thor what was happening and gave him her iron gloves and magical belt and staff. Thor killed Geirrod, and all other frost giants he could find (including Geirrod's daughters, Gjalp and Greip).
