Biter is a mute criminal from King's Landing with filed teeth. Along with Rorge and Jaqen H'ghar, he was fished out of the dungeons by Yoren and forcibly recruited into the Night's Watch. He is accompanying the rest of Yoren's new recruits northwards to the Wall.
Biter, alongside Rorge and Jaqen H'ghar are kept inside a cage for their trip to the Wall. When Jaqen asks "Arry" (actually Arya Stark) for water, Rorge demands beer and insults Arya, who says that he should have asked nicely and hits Rorge's hand with a stick. He recoils and then tries to grab Arya through the cage. Biter moves up behind Rorge and hisses as Rorge threatens Arya again.
The group is resting in a barn when they are roused to arms by Yoren and told they are being attacked. As they rush outside one man trips and drops his torch, setting a fire near the prisoner wagon. They are met by Ser Amory Lorch and a force of men loyal to House Lannister. Lorch points out the Gold Cloaks with him and says that they have come for Gendry, a royal bastard. Lorch orders Yoren and the recruits to drop their weapons. Yoren remains defiant and Lorch orders him shot.
Seeing their leader killed Gendry and many of the other recruits join the fight. Arya is distracted by Jaqen calling for help as the flames lick the bars of the cage. She hands him an axe before rushing to join the fray. They use it to escape the wagon. Gendry is overwhelmed and knocked down. As Arya runs round a corner she is knocked over and taken prisoner along with the other survivors.
Rorge, Biter and Jaqen are inducted into the Lannister army. They serve at Harrenhal, where their former fellow recruits are also taken as captives. Arya approaches Rorge and Biter looking for Jaqen. Rorge repeats his earlier threats and shows no acknowledgement of her saving his life.
Arya and The Hound come across a homestead recently burned and pillaged by Rorge and Biter. After granting a mortally wounded peasant a merciful death, the Hound is suddenly ambushed from behind by Biter who sinks his teeth into his flesh. The Hound quickly overpowers Biter and snaps his neck, killing him. Rorge then attempts to accost them before being recognized and slayed by Arya.
Later, the bite wound inflicted by Biter begins to fester due to the Hound's fear of cauterizing it with fire.
Biter is a Night's Watch recruit from the prisons of King's Landing. When the Lannisters attacked their northbound party, Arya Stark set biter free, along with Rorge and Jaqen H'ghar. Biter, who has sharp, filed-down teeth, was killed by Sandor " The Hound" Clegane after he bit a chunk out his neck.