Cauldron Borne: Dead bodies are put into a magic cauldron and come out as invincible undead warriors, who’s weakness is that the further they get from the land controlled by the bad guy (who’s name I can’t remember) the weaker they get.
Huntsmen: Groups of fighters, when one is killed the rest grow stronger to make up for it, so if you kill all but one he’s (it’s?) really really strong.
Gwythaints: I’ve always pictured them as medium sized black dragon things.
All this is from when I read the books as a kid, so the details may be a bit fuzzy, but I believe it’s more or less accurate. I keep thinking Huntsmen of Anubis, but I’m not sure of that’s their full name or not.
Tolkien coined (or discovered, take your pick) the term “orc”, an Elvish word for what the more down-to-earth characters like hobbits call “goblins”. Anything else that refers to Orcs (or Ents or Balrogs, for that matter) is a reference to Tolkien.
I’ll differ right back, bibliophage. It’s quite possible that a word with the same pronounciation and spelling occurs in Old English, but that doesn’t mean that it’s the same word. Would you argue that the Latin word for “five plus one” is the same as the English word for intercourse? Even so, the OE word for “demon” isn’t the same as the Elvish word for “goblin”.
“A different word orc, alluding to a demon or ogre, appears in Old English glosses of about AD 800 and in the compound word orcneas (“monsters”) in the poem Beowulf. As with the Italian orco (“ogre”) and the word ogre itself, it ultimately derives from the Latin Orcus, a god of the underworld. The Old English creatures were most likely the inspiration for the orcs that appear in J.R.R. Tolkien’s The Lord of the Rings trilogy.”
Encyclopedia Britanica
Tolkien used a lot of Old English derivations for names and language in his work. I think it entirely credible that he used this one.