killah black may or may not have ever been a real person. Most likely, killah black represents a concept put forth by Mobb Deep
and various members of Wu Tang in the early nineties. Killah Black is a name given to a close friend that you would frequently smoke blunts, drink liquor, pull stick ups, and get into trouble with. Killah Black had periodic run-ins with the law, and spent his fair share of nights in the pen. However, if you were to ask Havoc or Prodigy about Killah Black's illegal activities, they would never tell you due to loyalty and love. Killah Black may also be a code name used to avoid saying real names over the phone.
"I'm fallin' and I can't turn back, or maybe it's the words of my man Killah Black, that I can't say, so it's left an untold fact."
-Mobb Deep (Survival of the Fittest)