Despite the tension between gods and giants, there was a fair amount of contact on an individual basis, and a number of the gods had
relationships with giantesses. One of these was Loki, who had three monstrous children by his giantess wife.
His daughter Hel became ruler of the underworld. One son, Jormunagund, was a serpent who grew
so large that he stretched all the way around the earth. The other son was Fenris, a wolf so powerful that he terrified the gods until they tricked him into allowing himself to be tied up with a magical chain which bound him until the end of time.

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The Valkyries

The Valkyries were originally priestesses of the goddess Freya, but became warrior-maidens in the service of Odin. They chose which warrior would be slain on a battlefield to join Odin in Valhalla for the coming of Ragnarok.

The Giants

There were three types of giant:

Normal giants
Fire giants
Frost giants

The giants were all part of the Vanir and so against the Aesir, and at the time of Ragnarok, would cross over Bifrost and break it. They
would fight against Odin and the other Aesir at Vigrid. The normal giants lived in Jotunheim, the fire giants lived in Muspelheim, and the frost giants lived in Niflheim.

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