Wallen

Wallen is a character in Game of Thrones. He is played by Barry O'Connor.

Wallen is a wildling, and apparently a deserter from the Night's Watch (he is credited as 'Night's Watchman').

Season 1
Stiv, Osha and Wallen flee south of the Wall, apparently in fear of the return of the White Walkers. In the woods near Winterfell they stumble across Bran Stark and decide to steal his horse. Realising his importance, they ponder taking him prisoner and returning him to Mance Rayder, the king-beyond-the-wall, for a reward, but decide against it. Robb Stark intervenes and kills Wallen and disables Osha. Stiv is killed by Theon Greyjoy.

In the books
In the Song of Ice and Fire novels Wallen is a member of a band of wildlings who manage to evade the Watch to seek succor in the lands to the south. He is an associate of Osha and Stiv.