Ymir the Ice Giant – Ymir the primeval being from which the realms were made
https://www.wizard101central.com/wiki/NPC:Ymir#ixzz7gHoUqVnJ
https://www.wizard101central.com/wiki/Location:Nastrond#ixzz7gHowqVMO
https://en.wikipedia.org/wiki/Ymir
Ymir is an Ice Giant summoned by Ice Wizards during their Level 48 Quest. His true form is that of the Ice Titan, sleeping beneath Wintertusk in Nastrond. Wizards must prevent The Coven from waking the Ice Titan, Ymir, and bringing about the Everwinter.
In Norse mythology, Ymir, also called Aurgelmir, Brimir, or Bláinn, is the ancestor of all jötnar. Ymir was a primeval being who was born from venom that dripped from the icy rivers called the Élivágar, and lived in the grassless void of Ginnungagap. Ymir gave birth to a male and female from his armpits, and his legs together begat a six-headed being. The grandsons of Búri, the gods Odin, Vili and Vé, fashioned the Earth from his flesh, from his blood the ocean, from his bones the mountains, from his hair the trees, from his brains the clouds, from his skull the heavens, and from his eyebrows the middle realm in which mankind lives, Midgard
The current list of all the (known) Grizzleheim/Wintertusk references are located here.
Although I am well versed in Pop Culture references, I do not claim to have caught them all. Let me know your favorites in the comments and if I’ve missed one you caught, let me know so I can add it to the list.
Text for this article is excerpted from the linked wiki pages
Ymir image is from Wizard101, and are copyright of KingsIsle Entertainment.
Ymir illustration by Lorenz Frølich borrowed from Wikipedia and is in the public domain
Image usage qualifies as fair use under US copyright law.

