An amazing, black superhero
He disappears at night, can steal better than Catwoman, can jump 20 feet vertically, and can run faster than Usain Bolt. His weakness is water, so he is the only adult capable of drowning in a kiddy pool.
After Niggaman stole the Crown Jewels, he lay down in the middle of the black street. The cops were never able to find him.
The name of the protagonist Delapore's cat in prolific (and very dead) horror writer H.P. Lovecraft's short story "The Rats in the Walls". In a 1953 re-release of the story, the cat's name was changed to Black Tom.
Spoiler alert: The house is swarming with spectral rats (lovecraft be trippin') and Nigger Man is the only person able to sense them.
Now, any well adjusted member of society might think to oneself; why in the everloving fuck would any writer name a character, even a cat, Niggerman? The nature of the naming is never even explained. Lovecraft himself, however, actually had a cat named Nigger Man.