You may also be looking for Sergey a multiplayer character in GTA IV.
Sergei (Russian: Сергей) is a member of the Faustin Family and appears in Grand Theft Auto IV. He is Vlad's henchman and works for Mikhail Faustin. He first appears in the mission "Bull in a China Shop" having a drink at the bar in Comrades and then appears a second time in the mission "Clean Getaway" sharing an anecdote with some of the other customers. During Final Destination Dimitri mentions he has a friend in courts.
If the player would have failed the random encounter with Mel the first time, the second time, when talking to Niko, he'll mention that one of his reasons to stop drinking was "not hanging around with losers like Sergei".