Geirröd is one of Thor’s mightiest enemies. Geirröd is the father of Gjalp and Greip. Geirröd and his two daughters Gjalp and Greip are dead. Once Loki had once taken the shape of a hawk and had been captured by Geirröd. The only way Loki would avoid death was to promise to bring Thor to Geirröd’s hall, without his power belt and Thor’s hammer. Because Thor trusted Loki, he agreed to come to Geirröd’s hall, without his belt and the hammer Mjölnir.
Fortunately for Thor, they made a brief stop by a giant named Grid, and she warned Thor about the plan while Loki was asleep. She loaned him, her own strength belt, magical iron gloves, and her scepter. Thor fully equipped, he and Loki traveled to Geirröd’s hall the next morning. When they arrived, Geirröd was not home, but they were met by the servant. But it was not long before Gjalp and Greip tried to kill Thor, by lifting his chair and smash his head against the ceiling.
Thor used the wand to force the chair down, so it was instead Gjalp and Greip that was crushed underneath the chair. But then came Geirröd himself, and by using a tong, he picked up a red hot iron ball and threw it at Thor, Thor caught it with the gloves he had loaned from Grid. Furious at this behavior towards him, Thor threw the still burning, red-hot and steaming iron ball back through the hall, directly through an iron pillar, and deep into the belly of Geirröd. Geirröd and his two daughters Gjalp and Greip were dead, and Thor and Loki left the house, and returned to Asgard.