In Norse mythology, Gylfi (Old Norse: [ˈɡylve]), Gylfe, Gylvi, or Gylve was the earliest recorded king of Sviþjoð, Sweden, in Scandinavia. He is known by the name Gangleri when appearing in disguise. The Danish tradition on Gylfi tells how he was tricked by Gefjon and her sons from Jötunheim, who were able to shapeshift into tremendous oxen.