 Ymir is mentioned in two books of the "Prose Edda"; "Gylfaginning" and "Skáldskaparmál".Ymir is first mentioned in chapter 5 of the prior, in which High, Just-As-High, and Third tell Gangleri (the disguised mythical king Gylfi) about how all things came to be.The trio explain that the first world to exist was Muspell, a glowing, fiery southern region consisting of flames, uninhabitable by non-natives.