Geirrod

In Norse mythology, Geirröd was one of the Jotuns and father of Gjálp and Greip.Loki was flying as a hawk one day and was captured by Geirröd. Geirröd, who hated Thor, demanded that Loki bring his enemy (without his magic belt and hammer) to Geirröd's castle. Loki agreed to lead Thor to the trap. On the way to Geirröd'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 Geirröd, followed by all other frost giants he could find (including Geirrod's daughters, Gjalp and Greip). This story is told in Þórsdrápa.
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[Norse] A frost giant and father of two daughters, Gjalp and Greip. He was a bitter enemy of Thor, and having captured Loki (when Loki was flying around as a hawk) received from him a promise that he, Loki, would bring Thor to Geirrod's castle without Thor having his magic belt and magic hammer. Loki did as promised and led Thor into the trap. On the way there, though, they stopped to rest at the home of a giantess named Grid. She told Thor what was up when Loki left the room, and gave him her magic belt, iron gloves and magic staff. Needless to say Thor used each with supreme efficiency and slew Geirrod, his daughters and all other frost giants in the vicinity.