The Nark character is quite funny (silly), but at the same time is a cruel killer. It's not a fact, but maybe if he doesn't like something in the behavior of his friends, he can screw them up too (you never know, because of the side effects of drugs). 
If you hit a Drug Addict, he will start hissing at you. 
And when stroking, purr like a cat
He is a breed of Maine Coon
The narc is also terribly aggressive and dangerous, he knows Russian and English, and also often jokes with black humor.