In the
Third Age of the Sun, the ring lord
Sauron took the some of the ancient
Trolls
Melkor had bred in
Angband, and from them fashioned another
race who were known as the Olog-Hai in the tounge of
Mordor. They were like Trolls in
size and
strength, but faster and more
cunning, like the
Orcs. Their scaly skin was
hard as stone, and they were unafraid of the
daylight, which was
deadly to the Troll race. Sauron bred them to be fierce,
ravening beasts and awesome
fighters,
hungering for
the flesh of their enemies.
Yet strong as they were, the Olog-Hai were destroyed at the end of the Third Age as Sauron was defeated. Without his guiding will, they reeled and wandered senselessly around. Lifting no hand to defend themselves, all were slain or lost. The histories of the Fourth Age of the Sun speak nothing of the Olog-Hai, for thay had vanished from the World forever.
In
Nethack, the Olog-Hai are a
terrible enemy unless you're pretty high
level. They are level 13, with an
AC of -4 and three attacks, with the ability to
wield weapons. And, of course, being trolls, you have to kill them many times unless you have some means to dispose of the
corpse.
Information from J.R.R. Tolkien's The Return of the King, David Day's A Tolkien Bestiary, and Dylan O'Donnell's Nethack spoilers.