Wex

Wex is a background character in the second season. He is played by an unidentified extra and debuts in "Valar Morghulis". Gelmarr is an ironborn raider and member of the Sea Bitch crew. His name is one of those called out in Theon Greyjoy's speech as a name which will be remembered in the Iron Islands after the die as heroes.

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. The horse is an aggressive black stallion which Theon Greyjoy names Smiler for its tendency to try to bite people. Wex's father bought the horse, but couldn't control it as islanders don't have great horseback riding skills. Theon has ridden his whole time at Winterfell so doesn't have this problem. He gets a good deal on the horse if he takes Wex as squire. Wex is with Theon when he mets Asha (called Yara Greyjoy on the show. Wex's eyes bug out at seeing her and Theon and their later flirting which Theon takes as a sign the lad is shy. When he finds out who Asha is Theon realizes that Wex knew all the time, but being mute couldn't say. Seeing Wex smiling, He gives him a swat on the back of the head and tells him to learn how to talk.

Wex goes with Theon 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, shaming other men into agreeing to stay as well. Only 17 of Theon's men agree to stay with him to face the attack of the 500 men lead by Rodrick Cassel to free Winterfell, the others including ten left by Asha go before they arrive.