Cyclops

The Cyclops is a one-eyed giant species known of in Daventry and the world.

The Door into Mountain is said to have possibly been cyclopean stonework set into the living rock. It consisted of a huge door, girded with iron bands. The whole construction looks as if it was meant to repbel armies--large armies. The size of the door indicated the one who built it was very large person indeed.

Behind the scenes
One of the questions in King's Questions refers to Cyclops and how they had never appeared in the games.

They originate from Greek mythology.