What primordial giant was killed to create the world?

The story behind the answer

Ymir is the primordial giant in Norse cosmogony. In the void of Ginnungagap, frost and fire birthed Ymir; later, the gods Odin, Vili, and Vé slew him and fashioned the cosmos from his body: flesh became the land, blood the seas, bones the mountains, skull the sky, and eyebrows the wall of Midgard.

This violent creation myth shows order emerging from chaos. To avoid confusion: Fenrir is the wolf fated to kill Odin at Ragnarök; Nidhogg is the dragon gnawing at Yggdrasil’s roots; Gullveig is the seeress whose burning sparked the Æsir–Vanir War. Memory tip: “Why (Y) is there a world? From Ymir.”