In Curse Of Strahd, Mishka ambushed the Pack, springing at Ghalwin Forrester from his well. However, Lancelot detected and barked at him before he could surprise the paladin, who effortlessly rebuffed him before Atlas Atruvian put the boy to sleep. The manacled him to the well's pulley system, and he asked nicely if he could kill them. After an unproductive back-and-forth, The Pack grew tired of him and left to speak with The Abbot.
Mishka was a Mongrelfolk created by The Abbot, residing in the Abbey of Saint Markovia. Like all other members of the Belview family, he lived a short and tortured life. With a wiry, spindly build, Mishka possessed the ability to climb on walls and ceilings, and lived in a well in the courtyard of the abbey. He had three red spider eyes on the left side of his face, while the right side appeared human, though wolf's fur enveloped his face. A frog's foot was in place of his left hand and he had a raven's talon where his right foot should have been.
Mishka developed a taste for killing to the point where it became his whole reason for being, though he was not an especially fearsome combatant. He grew a habit of killing small creatures that entered the courtyard, such as rabbits and bats, and lived in the well in the middle of the abbey. Growing bolder, he tried to kill his older sister Marzena Belview, but she flew away as he lunged. The Abbot's right-hand man, Clovin Belview, noticed her escape attempt and shot her down with a crossbow.
The Abbot healed Marzena, but as punishment, Clovin had her chained to a post in the courtyard. Though she was close to Mishka's well, Clovin forbid him from ever going further than thirty feet from his home, and the mongrelman obeyed, spending his days in the well unless given the chance to pop up and scare visitors.