In the Poetic Edda poem Hymiskviða, the giant who accompanies Thor on his fishing trip is Hymir.
Thor visits Hymir and seeks a large enough cauldron for the gods’ feast. During the journey, Thor and Hymir go fishing, and Thor uses an ox head as bait. His catch is the Midgard Serpent, Jörmungandr, one of the most dangerous beings in Norse mythology. Thor strikes the serpent with his hammer, but the story’s ending differs among surviving traditions.
In Hymiskviða, Hymir becomes frightened and cuts the fishing line, allowing the serpent to escape. In other literary accounts, especially Snorri Sturluson’s Gylfaginning, Thor pulls the serpent aboard before Hymir severs the line. These versions are often combined in modern retellings, which can make the details seem contradictory.
Hymir is therefore distinct from Þrymr, the giant in Þrymskviða who steals Thor’s hammer. Their similar-looking names are a common source of confusion.