Ymir
Ymir is considered the Origin of life. There are many gaps in the account of how all the creatures of the world came to be descended from this one creature, or if there were others; but not everything can be known. He is considered a Jotun as it is not believed he was attuned to any of the Runes; though his exact nature is uncertain. From him the line of the Aesir Gods can be established, from his Son Buri who was the first God to use the term Aesir.