Euron Greyjoy

Euron Greyjoy, is an unseen character in Game of Thrones. He has only appeared in the House Greyjoy family tree issued by HBO. He is an uncle of Theon Greyjoy.

Background
Euron Greyjoy is the younger brother of Balon Greyjoy, head of House Greyjoy, Lord Reaper of Pyke and self-fashioned King of the Iron Islands.

In the books
In A Song of Ice and Fire, Euron is a wildly unpredictable man, known for his delight in playing vicious mind games and waging psychological warfare on anyone around him. He is hated by all his brothers, particularly Victarion, for this reason. He wears a patch over his left eye, and is nicknamed "Crow's Eye", though it is unclear what he hides beneath the patch.

Several years ago, Euron seduced and impregnated Victarion's wife, which drove Victarion to beat her to death in his rage. Only the taboo against kinslaying kept Victarion from killing Euron too. As punishment, Balon exiled Euron from the Iron Islands, so he is not present when Theon returns to Pyke. Victarion deeply hates Euron for that and wishes him dead.