In Asgard, long before even Thor was born, the Grim God Rimthursar collected five mythical beings as Kyrie, Fairgold, Grult, Slithgarn and Borna.

For a time they were content enough in his menagerie, but then he became ambitious and sought to use them in a campaign against Odin himself. When they refused to act as his quislings, Rimthursar slew them all in a rage. Sealing their souls each in a single drop of blood, he then stained the bottom of his silver chalices with the five droplets, freezing them forever in silver.

Then, in a final pique of fury, he cast them out from Asgard, hurling the chalice down to the lower realm of Midgard, or Earth.

Origin

The Menagerie of Rimthursar was created by Doug Moench and Keith Pollard in 1982 and first appeared in Thor # 320.