Brynden Tully

Ser Brynden Tully, popularly called The Blackfish, is a character in Game of Thrones. He is expected to debut in the second season and has not been cast at this time.

Brynden Tully is the younger brother of Lord Hoster Tully and is a respected knight and formidable battle commander. He is the uncle of Catelyn Stark, Edmure Tully and Lysa Arryn.

In the books
In the Song of Ice and Fire novels, the Blackfish is a canny and respected warrior. In the novels he is first encountered serving in the Vale of Arryn, where he works on behalf of his neice, the Lady Lysa, following the death of her husband. After Catelyn asks for his assistance, he agrees to return to the Riverlands and help in the growing struggle against the Lannisters.

In the TV series, to cut costs, Brynden's activities in the Vale have been taken over by Ser Vardis Egen. Brynden himself will appear in Season 2.