Wikipedia
The Chamuco (a Mexican word means "devil") or Mexican Pitbull is a dog breed not recognized by any Canofile association. It is originated of the center of Mexico, it was developed in this country in the 1970s, product of the accidental or intentional crosses of the American Pit Bull Terrier with the now extinct Mexican Bulldog, street dogs, American Bully, Pitbull Blue, Staffordshire bull terrier, American Staffordshire Terrier, and probably with the Boxer. Its name comes from the Mexican slang Chamuco, which means devil because of its temperament and tenacity. Also it called Mexican pitbull or miniature pitbull, but actually is Dogo of Mexican origin.
It is a little known race and even denied, because it is not the kind of dog that it may be purchased at any pet store because it are breeding and selecting clandestinely, since it is basically a fighting dog. Rarely is found like pet in popular areas of the Greater Mexico City, Metropolitan area of Puebla, Metropolitan area of Pachuca de Soto, Metropolitan area of Queretaro and Metropolitan area of Toluca.
The Chamuco usually presents different colors, being preferred the black, coffee and brindle. It is not customary to clip the ears or the tail, the people who raised to fight prefer dark colors, so it will not notice the blood and of small size, as this helps them hide. It has a phenotype defined, requires little care, is of small size, slender but musculous, aggressive towards other dogs because of its strong self-preservation, but almost devoid of instinct of territoriality so it is very confident to humans, very playful and protective with the children.