A massive, bald albino, Biter is named for the fact that his yellowed teeth are filed to points. He doesn’t speak, instead hissing and growling.
The actor in the role is not depicted as albino or bald, nor is he albino. His teeth are shown to be filed into points, however.
Biter, along with Jaqen H’ghar and Rorge, is one of three dangerous prisoners that Yoren transports from King’s Landing to the Wall. The three are nearly killed when Amory Lorch’s men attack, but Arya Stark provides them an ax with which they are able to free themselves. Rorge and Biter eventually join Jaqen in becoming soldiers in the Lannister host.