Ettin

Ettin is a three-headed giant in English fairy tales.

Eymology

Ettin is related to the word Jotun from Norse mythology.

In The Red Ettin, an ettin of Ireland steals the daughter of King Malcolm, king of Scotland.

Tolkien most likely had this in mind when he described Bilbo's adventures in the wild Ettenmoors region (where he met three angry trolls) just north and west of Rivendell.
In wikipedia:C. S. Lewis's wikipedia:The Lion, the Witch and the Wardrobe the Ettins are mentioned in passing as an evil species in league with the wikipedia:White Witch.
In the fictional wikipedia:Stargate universe, the people of the Asgard-protected planet Cimmeria refer to the wikipedia:Goa'uld as 'ettins'.
The ettin from the wikipedia:Dungeons & Dragons role-playing game is a two-headed giant.
The name of a two-headed ogre-like creature in wikipedia:HeXen, wikipedia:Stonekeep and the wikipedia:Ultima games. Also in the role-playing game Fate.
A species in the game wikipedia:Creatures.
Large, muscular creatures in wikipedia:Guild Wars. They are about one and a half times as big as a human, and carry around large clubs as weapons. They are notoriously deformed, hunched and have a distorted face.