Agent Runcible first appeared in Book One when the SNAPA agents came to inspect the griffin cubs. He appeared next in Dragon on Trial when Pelly was seemingly murdered by Scratch , aggressively accusing Scratch and proposing that they terminate him immediately. He was later accidentally glitter-bombed with silver dust by Zoe Kahn and discovered to be a werewolf, bitten on assignment four years ago. At the end of Dragon on Trial, he holds Scratch's trial, and is later found in the trial arguing with Ruby Kahn and seemingly partially turning into a wolf. He tries to send information on minor things in the Menagerie that were messed up on, and is blackmailed by Melissa Merevy into being quiet from threats to expose all the SNAMHP rules he had broken as a new werewolf. In Krakens and Lies , he stays around the Menagerie, checking on things and trying to report the Menagerie's incompetence to SNAPA.
Agent Runcible is cold, businesslike, and seemingly wants to shut down the Menagerie. He is thought of as the unfriendly agent in contrast to Delia Dantes, and is slightly arrogant.