Endrew Tarth

Endrew Tarth is a minor character that debuts in "Two Swords". He is a knight of House Tarth and a sworn brother of the Night's Watch, serving as the Master-at-arms at Castle Black. He's portrayed by Dez McMahon.

Season 4
Ser Endrew oversees the archery training of new recruits of the Watch who have arrived to Castle Black along with Ser Alliser Thorne and Janos Slynt.

In the books
In the A Song of Ice and Fire novels, Ser Endrew Tarth is summoned from the Shadow Tower to serve as the new Master-at-arms of Castle Black after Lord Commander Jeor Mormont decides to send Alliser Thorne to King's Landing.

His relation with the main branch of House Tarth is not mentioned.