The Frost Giants

The first living being formed in the primeval chaos known as Ginnungagap was a giant of monumental size, called Ymir. When he slept a jötunn son and a jötunn daughter grew from his armpits, and his two feet procreated and gave birth to a son, a monster with six heads. These three beings gave rise to the race of hrímþursar (rime thurs), who populated Niflheim, the world of mist, chill and ice. The gods instead claim their origin from a certain Búri. When the giant Ymir subsequently was slain by Odin, Vili and Vé (the grandsons of Búri), his blood (i.e. water) deluged Niflheim and killed all of the jötnar, apart from one known as Bergelmir and his spouse, who then repopulated their kind.