A 'chimpnigger' is the ugliest nigger you can find in the whole Creation. The nigger is so Goddamn ugly that you can mistake him for a very ugly monkey.
Portmanteau of Chimpanzee and Nigger. Chimpanzees are extremely violent, and very promiscuous, just like niggers. Niggers are also prone to violent outbursts, known as chimping out". Therefore a nigger in the middle of a chimp out may be described as a chimpanigger.
Chimpaniggers were on the news again last night. They stabbed a teenager in Brixton, shot someone in Streatham High Street and violently raped at least 30 human women.