Elves
The elves are luminous beings, “more beautiful than the sun,” whose exalted status is demonstrated by their constantly being linked with the Aesir and Vanir gods in Old Norse and Old English poetry. The lines between elves and other spiritual beings such as the gods, giants, dwarves, and land spirits are blurry, and it seems unlikely that the heathen Germanic peoples themselves made any cold, systematic distinctions between these various groupings. It’s especially hard to discern the boundary that distinguishes the elves from the Vanir gods and goddesses.
The elves that have joined the material plane were either tired of their home and wanted to explore the world or were exciled. Either way these elves would never return to their home plane.