Greetings.

I'm currently re-reading the silmarillion and it mentions (In the War of wrath)that along side balrogs, orcs, dragons, werewolves etc their was mentioned thousands of other evil demons joined the war.

My question is if anyone knows. What exactly were these demons.
i.e were they like Ungoliant or lesser balrogs (corrupted maiar), or something completely different.

Any comments are appreciated.

cheers.