Peer had wavy hair and the thin outline of a mustache. During missions, he wore the standard Scout Regiment uniform.
During the 57th Exterior Scouting Mission, Peer argues with Dieter and Jurgen over the recovery of their friend Ivan's body. He then scolds Dieter for insulting Erwin and Levi when Dieter says they do not have any human feelings at all.
Shortly afterwards, Peer rides on the back of the wagon carrying the soldiers' corpses en route to Calaneth District, the bodies of Levi's squad among them. He spots the two Titans pursuing the wagon, cursing and firing a smoke round to signal the Titans detected. Under Levi's instruction, the corpses are dumped to reduce the weight of the wagon and subdue the approaching Titans.
Peer is among the Scout Regiment soldiers who participate in the mission to rescue Eren Jaeger from Bertholdt Hoover and Reiner Braun. When Titans are spotted during the mission, Peer reports the sighting to Erwin.
After the Scouts recover Eren, they begin to retreat to Wall Rose but are soon stopped when Reiner begins using his Titan form to throw Titans into their escape path, blocking them. Erwin is knocked off his horse in the ensuing chaos, and Peer is devoured while trying to protect him.