Wun Weg Wun Dar Wun
From A Wiki of Ice and Fire
Wun Weg Wun Dar Wun is a giant who came across the wall when the wildings led by Leathers were let across the wall by Jon Snow he is calledWun Wun. He speaks the Old Tongue after a fashion and was as strong as twelve men.
He did not taste wine before he came to Castle Black, but was developing a liking for it. he sleeps in the entry hall of Hardin's Tower. After Jon Received a letter Ramsay Bolton he heard Wun Wun roar and a man scream. When he arrivesat Hardin's Tower finding a bleeding Wun Wun is smashing dead Ser Patrek against a tower wall.