A type of confectionary which is black in colour and round. Some people like to suck on them, others prefer to lick them. They originate from Africa. Nowdays, due to the phobia of using the word "nigger", they're often known as blackballs.
And yes, this is true. There seriously is a confectionary called "niggerballs". Look it up.
A special insult reserved for the worst types of people on the planet. While for some terms such as "asshole", "douchebag", or even "mcfaggletits" succinctly do the job, a niggerballs is the worst of the worst of people who suck at life. Literally meaning the gonads of a male of negroid descent, because this person is the dark, hairy, smelly, crusty scrotal sack on the body of society. Total King Niggerballs may be used in rare occasions for the absolute most despicable people, but there must be an consensus that this person is shitty enough to be worthy before this term is bestowed.
"So you drank all my booze and crashed my car after driving it drunk? You are a complete niggerballs!"
"Did you hear what Omar did today?"
"No, what did he do now?"
"He stole lottery tickets from his dad's gas station and got fired."
"Dude, what a niggerballs!"