The title of this article is conjecture based on information revealed in the A Song of Ice and Fire novels and may be subject to change.
Builders!" ― Othell Yarwyck
Othell Yarwyck is a recurring character in the first, second and third seasons. He is played by guest star Dennis McKeever and debuts in " You Win or You Die." Othell Yarwyck is a senior member of the Night's Watch.
Othell Yarwyck is
First Builder of the Night's Watch and a member of House Yarwyck, a noble house of the Westerlands sworn to Casterly Rock. He is based at Castle Black and is tasked with organizing the builders in maintaining the Wall and the castles belonging to the Watch.
Yarwyck is present for the induction of the new recruits at
Castle Black. He calls for the builders after the Lord Commander's speech. He is also present when the bodies of  Othor and Jafer Flowers are returned to Castle Black.
Yarwyck takes part in Lord Commander
Mormont's Great Ranging. He is among the officers that takes shelter inside Craster's Keep and is present when Mormont speaks with Craster about Mance Rayder's actions and plans. The  Night's Watch are forced to move on when Jon Snow is caught spying on Craster leaving a newborn son in the woods.
Yarwyck survives the
White Walkers' attack against the Night's Watch camp atop the Fist of the First Men and joins the survivors' march to Craster's Keep.
* - Uncredited appearances
In the books
novels, Yarwyck is also present for the induction of the recruits and has the same single word line. However, he doesn't take part in the Great Ranging beyond the Wall.
A Song of Ice and Fire