Moriarty, the Hound's archenemy, is depicted differently from the rarely appearing mafia donnish Moriarty in the books. In this iteration, he works personally on his schemes without any support network, frequently encountering Hound and his allies as the main antagonist in the majority of the episodes. Despite this, he retains his intellectual prowess and is a master inventor, often responsible for the steampunk technology seen in the show. This includes his personal "steam car," a unique vehicle resembling a cross between a tractor and a tank rather than a traditional car. Moriarty's plans can be incredibly complex or outlandish, often relying on unconventional acts that require Hound's keen insight to unravel. Sometimes, Moriarty acts as a mercenary for other criminals pursuing objectives he wouldn't typically pursue. Additionally, in this version, Moriarty is visually portrayed resembling a gray wolf.