Tristan Mudd at some point he joined the Night's Watch, and eventually rose to become its Lord Commander. Although he is not specifically described as having been terrible as a leader, dialog surrounding his name would suggest his name is listed along with other examples of implied poor quality among past Lord Commanders.
In the books
In the A Song of Ice and Fire novels, his story is the same.
Eddison Tollett (acting)
|Former Lords Commander:|
|Castles of the Watch:|