More complex then just a Coon and a Nigga, it's widely used as a an adj. to regular coon. For example, people may say "damn he a
black ass nigga" when clearly stated the person was already "black" before "nigga".
A coon is someone who is typically a sell-out, or is a
representative for the
African-American stereotype, so a coon ass nigga is a coon to the eXtreme
Flava Flave is a one coon ass nigga.
50 cent is hella coon ass nigga.
"Damn tyrone, G-Unit is a buncha coon
ass niggas"
"Damn that girl tiquanda datin that coon ass nigga, can't even see his ass
in the dark."
"Damn blubaugh one hella wigger coon ass nigga
wanna be"