Wex

Wex is a background character in the second season. He is played by an unidentified extra and debuts in "The Ghost of Harrenhal" though first identified in "Valar Morghulis". Gelmarr is an ironborn raider and member of the Sea Bitch crew.

In the books
In the Song of Ice and Fire novels, the only Wex is Wex Pyke, the bastard son of Sargon Botley of Lordsport. He's twelve years old and born mute. He becomes Theon's squire as part of Theon's deal with Lord Botley to buy a horse from him. He later takes part on the raid of the Stony Shore, the assault on Winterfell and the hunt for Bran and Rickon. When Theon calls on his men to stand alongside him against the Northmen trying to retake the castle, Wex is the first to stand with him.