Boris was a minor character from the third season of Gotham, appearing in the season premiere "Better to Reign in Hell..." He was a mobster who was hired by Butch Gilzean for a half-baked scheme to get him and Tabitha Galavan back together.
One night, Boris and two of his goons visited the Sirens Nightclub after hours when they learned that Barbara Kean didn't have the Penguin's backing. When Boris stated his intention to take the club from her, Barbara briefly put on a facade of fear before breaking down in maniacal laughter. While Boris stood there confused, Tabitha appeared from behind the backs of his henchmen and slit their throats. Barbara then grabbed Boris' gun from him and beat him with it.
The next day, the Penguin and Butch arrived at the club to find Barbara and Tabitha holding Boris hostage. Barbara revealed that Butch had hired Boris and his men to shake them up as part of a plan to get back together with Tabitha. Penguin, irritated by the whole affair, drew a gun and shot Boris in the head.