Typically called a "pit bull"... which I'm sad to share, because it will bring out the usual breed-haters. =^(
Similar to Pit Bulls, but a bit smaller, more stable. ....and an AKC registered breed.
Pits are more like the American Staffordshire Terrier than the English variety. But again, they're not identical.
Nope. A "pit bull" is a cross bred between a Staffordshire and an English bull terrier. It's not a 'purebred' dog in that sense, although now the cross-bred is established well enough and is now bred as a "pit bull"