Ymir

Ymir, is the primordial ancestor of the Frost Giants. He is associated with the Norse Pantheon. Ymir is truly massive, on a scale of miles in height. His skull is large enough to form the dome of an entire world's sky, and his body as massive as an entire planet. Little else is canonically known about Ymir's appearance or personality.
he humans of Midgard tell that the world began in the void of Ginnungagap, with frozen Niflheim to the north and fiery Muspelheim to the south. Layers of ice from Niflheim slowly formed across the gap until they reached Muspelheim, where hot winds blew and began to melt the ice.
From this melting Primordial ice rose Ymir, a truly massive Frost Giant. Drops of Ymir's sweat formed the first Frost Giants. Next rose the great cow Audhumla, whose milk sustained Ymir and the Giants. The cow Audhumla licked the salty rime stones and uncovered a man named Buri. From Buri's descendants came three sons: the gods Odin , Vili, and Ve.
The three sons murdered Ymir. Their reasons for this are uncertain. Ymir's blood flowed and drowned all of the Frost Giants except for Bergelmir, who survived and went on to be the progenitor of all living Frost Giants.
Odin, Vili and Ve built the world of Midgard, where humans now live, from Ymir's corpse. His skull became the blue sky, his brains the clouds, his blood the ocean, his hair the plants, and his shattered bones the rocks and stones. From his eyelashes they made a great fence to keep the giants out of the land of humans.
The Frost Giants still hold a grudge against the Aesir gods of the Norse Pantheon for the murder of Ymir. The name "Ymir" is given to some giants, particularly male Frost Giants, in honor of their progenitor.