mastiff

mastiffi An old breed of powerful, deep-chested, and smooth-coated dog used chiefly as a watchdog and guard dog.
1605: w:William Shakespeare|William Shakespeare, w:King Lear|King Lear, Act III, Scene VI

Avaunt, you curs! Be thy mouth or black or white, Tooth that poisons if it bite; Mastiff, greyhound, mongrel grim, Hound or spaniel, brach or him.

The Mastiff is a good fighter, and can kill a wildcat, taking the necessary punishment well, as we found out when we once trapped one of these small lynxes.