Posted by Ward on October 13, 2004
This may be simply a US expression, but it describes anyone who is just a mean son-of-a-gun. (being PC here) The comparison with the junkyard dog refers to the guard dogs used to patrol wrecked auto parts lots where the losses to midnight thievery would be great without the dogs presence. They are usually Dobermans or German Shepards, and are bred and trained to be rather intimidating and downright dangerous.
Is this used elsewhere in the English speaking world?