Along with Rand and a number of other bucks, Mo was sheltering in a cave during a rainstorm shortly after Picket Longtreader and Helmer entered First Warren. He claimed to be a loyal subject of governor Winslow Joveson, but also accused the pair of being part of the Black Band. Mo was surprised when they claimed to be from outside the city, and more so when he learned that they hadn't heard the song "Picket Packslayer".
He later fled the cave with most of his compatriots after one of the cave denizens was revealed to be the Teller.
Picket described Mo as a skinny rabbit with brown fur.