Amycus (Monsters of Mythology)

Bernard Evslin tackled lots of familiar monsters in this series - Minotaur, Medusa, Cyclopes, etc etc, but he also took on some lesser-known ones and wrote cool stories about them. In this book, Amycus is the offspring of a Cyclopes and a sea nymph, and apparently since his dad made this cool golden head for himself, his son was born with an exceptionally strong and metal-like head. Weird, but still good story.