A próxima linha de Gandalf é (ênfase minha):
Far, far below the deepest delving of the Dwarves, the world is gnawed by nameless things. Even Sauron knows them not. They are older than he. Now I have walked there, but I will bring no report to darken the light of day.
The Two Towers Book III Chapter 5: "The White Rider"
- Espíritos aborígenes (isto é, espíritos criados por Ilúvatar para habitar Arda no começo de sua criação) como Tom Bombadil
- Úmaiar, espíritos malignos alinhados com Morgoth que mais tarde ficaram loucos
- Criaturas criadas por Morgoth antes da rebelião de Sauron
Eu vou citar Martinez brevemente, porque ele concisa diz a única coisa que podemos dizer definitivamente sobre eles:
To say that they are older than Sauron implies that they existed in Middle-earth (Arda) before Sauron arrived.
"Valaquenta" seems to imply that the Maiar did not join the Valar until after the Valar began shaping Arda; Manwë called upon them to help drive Melkor off into other regions of the universe. But Arda was at this time still in a very fiery state. It seems unlikely to me there was anything living there. Tom Bombadil and other "aborigines" of Arda must have been created by Ilúvatar after Arda had cooled and become a habitable place. This would explain why Bombadil thought of Melkor as coming "from the outside".
Mas não sabemos nada de forma definitiva.