Pypar is a steward in the Night's Watch and a friend to Jon Snow.
Pypar was sent to the Wall for refusing to grant sexual favors to a lord at Acorn Hall while working as a singer. The lord accused him of stealing and he was sentenced to the Night's Watch and now serves at Castle Black. Pypar usually lies and tells people that he was arrested for stealing a wheel of cheese to feed his sister, who had not eaten for three days (it isn't clear if he really even has a sister).
Pypar, along with Grenn and Rast, is beaten bloody by Jon Snow in the training yard at Castle Black. They later threaten Jon in the armoury, but are encouraged to leave by Tyrion Lannister. Tyrion contrasts Pypar's background as a starving peasant to Jon's privileged upbringing in a warm castle with a master-at-arms eager to teach him in the art of combat. This encourages Jon to start training the others in swordplay, earning their respect.
Pypar and Grenn have become firm friends, with Pypar teasing Grenn about his slow wits. When Samwell joins the recruits and is beaten, Pypar holds Jon back as he attempts to interfere. He goes along with Jon Snow's plan to 'go easy' on the new recruit, annoying their Master-at-Arms Ser Alliser Thorne.
Pypar, Jon and Samwell are assigned to the stewards while Grenn is assigned to the rangers. Jon is upset that he has not gotten his desired appointment to the rangers. Pypar is annoyed by Jon's sense of entitlement and awkwardly tells Jon and Samwell that he was really sent to the Wall when as a singer at a nobleman's hall he refused to grant sexual favors to a noble lord. He didn't want to tell strangers the real reason. Samwell asks Pypar, who has a good singing voice, for a song, but Pypar is too embarrassed by his confession and walks off.
Pypar and Grenn are among the men who witness the arrival of the bodies of Othor and Jafer Flowers to Castle Black.
The dead men return as wights and Jon saves the Lord Commander from one of them. He is rewarded with the sword Longclaw and Grenn, Pypar and the others pass the sword around in the dining hall.
Grenn, Pypar and Sam ride after Jon when he abandons his post at Castle Black following the death of his father. They convince him to return by reciting their oaths.
Pyp remains at Castle Black while his friends are Beyond the Wall on Lord Commander Jeor Mormont's great ranging.
Pyp is present when Jon Snow returns to Castle Black after escaping from the wildings and being shot with arrows by Ygritte. At first, he doesn't think Jon can recognize him and Sam with his injuries. Jon stares at both of them and says their names with relief before being carried inside.
Pyp and other members of the Night's Watch receive news from a boy name Olly about how his entire village was massacred by a wildling raiding party. The meeting is interrupted by a single horn blast, which is revealed to be Grenn and Edd, who have managed to escape the chaos that occurred at Craster's Keep.
Later, Pyp is present in the dining hall when Jon Snow asks for volunteers to deal with the mutineers who are holed up at Craster's Keep.
The news of the wildling attack on Mole's Town reaches Castle Black. Sam is horrified by the news, believing he sent Gilly and her baby to their deaths. Pyp reminds Sam that he believed that everyone who went with Commander Mormont had died. Despite the odds, Jon, Sam, Grenn, and Edd all made it back to Castle Black alive.
As he is preparing for the attack on Castle Black, he starts shaking, and Sam comes over to comfort and empower him to conduct his duties. As Mance Rayder's army attacks Castle Black, Pypar defends the bridge with a crossbow but continually missed killing members of their army before retreating with Sam. Pypar and Sam get to cover, and continue to try to kill the members of Mance Rayder's army. When Pypar successfully kills a wildling, he gushes over this achievement with Sam telling him he has more to do. As he goes to shoot again, Ygritte launches an arrow at Pypar's throat, fatally wounding him. As he is struggling and choking on his own blood, Sam holds his head and tells him it will be alright until he dies.
After the arrival of Stannis Baratheon and his forces, Pypar is among the numerous bodies of fallen black brothers burned in Castle Black's courtyard.
A recruit who joined the Watch after he was accused of stealing, Pyp later revealed to his brothers that it was not theft, but the rejection of a highborn lord's advances, that sentenced him to a post on the Wall. Pyp remained at Castle Black while the rangers went out beyond the Wall. He died during the Battle of Castle Black, slain by Ygritte's arrow.