It is a common stereotype that black people smoke menthol cigarettes. If a non-black person is smoking a menthol cigarette it then becomes a niggarette.
Black people can not smoke niggarettes. It is presumed that their cigarettes are already menthol which is not abnormal.
Nigga + Cigarette = Niggarette
"I need a smoke. Could I get a niggarette?"
"I definitely prefer the menthol taste of these niggarettes over your cigarettes."
Brittney Spears has been known to smoke Niggarettes.