Elves were mythical creatures.
The First Doctor encountered elves and dwarves on Elbyon. (PROSE: The Sorcerer's Apprentice)
The Sidhe inspired the Leshy of Polish folklore, the Kachinas of Hopi mythology, elves and fairies among other mythical beings. (PROSE: Autumn Mist)
The True History of Planets was a book about elves and magic until it was rewritten as a text to support a revolution on dogworld. (PROSE: Mad Dogs and Englishmen)
Caligaris Epsilon Six was a holiday planet that was designed and constructed to resemble a fantastic medieval European version of Earth. It had genetically engineered elves, cyborg dragons and robotic fairies. (COMIC: A Fairytale Life)
In a shared dream induced by the Kantrofarri, the elves Ian and the Wolf acted as helpers for Santa Claus, aiding him in delivering Christmas presents. (TV: Last Christmas)
Mirkwood was a forest where elves lived. Giant spiders and an evil wizard were found there, but the Thirteenth Doctor admitted she usually only remembered the elves. (PROSE: Molten Heart)