When a white person is hanging out with any amount of black people and drops the word nigga. They immediately stiffen up and stay as still as possible in the hopes that the black people won't recognize they said the word nigga.
Some random white dude says nigga to a bunch of black guys, then the niggamortis occurs.
The death of a black man. Initially the name of the album "6 Feet Deep" by Gravediggaz, but they had to rename it due to the whiney cunts that found it offensive.
The posture/reaction of a black person when they see a police officer. Niggamortis occurs in just .1 of a second and in this time they decide if they should play it cool or run from said law enforcement.
When you fail at something in life (eg. failing an exam or not getting a job), go home and spend an hour just standing in the shower, propping yourself up against the wall with your eyes on your feet.
Caleb knew the only thing to do after he didnt get prefect was take a failure shower.