Murderuss / Russell Kroy is a character played by Snoop Dogg. He appears in the episode Mr. Monk and the Rapper.
Before he became known under his artist name Murderuss, Russell Kroy was a small-time drug dealer in San Francisco, who had frequent run-ins with Captain Stottlemeyer, then a beat cop. Since then, his career as a rapper had taken off, founding his own record label, Manslaughter Records, which turned out quite profitable for him. In 2007, one of the most popular rappers under his contract, Xtra Large, took an offer by Fresh Rhymes Records and abruptly broke off their collaboration. This led to Murderuss to openly threaten Xtra Large in interviews, as well as release a song called "Car Bomb" in which he aptly describes a murder by planting explosives in a car, ostensibly directed at his former associate. Unfortunately, only weeks after the single dropped, Xtra Large was killed in a car bombing, immediately making Murderuss prime suspect in the eye of the public. When police started to look into the accusations, he subsequently turned to Monk to help clear his name.
When Monk determined the killer to have been Manslaughter Records executive Denny Hodges at Xtra Large's tribute concert, after telling Murderuss and the police about it, he goes on stage to do the same to the attendants, but is booed by the crowd instead. Murderuss promptly joins Monk and begins rapping the summary in lieu of Monk, leading to Hodges' arrest. Grateful, Murderuss then offers him a position as head of security on his upcoming tour, which he politely declines.