junkyard dog

plural junkyard dogs

1. literallyAn aggressive dog which guards a scrapyard or junkyard.

   I saw nine dogs running en pack on South Washington Avenue ... They were making for a junkyard that appeared to be their headquarters ... And those junkyard dogs do make nights hideous for the neighbors

   1936 July 23, “Dan D. Lyon”, in Scranton Republican, page 4

2. broadlyidiomaticAn animal or person with an especially nasty and combative demeanor.

   Badder than old King Kong / And meaner than a junkyard dog

   1973 Jim Croce, "Bad, Bad Leroy Brown", from the album Life and Times (song lyrics)

   2 more examples

   House minority whip . . . Gingrich has earned enmity in abundance for his junkyard-dog tactics.

   1992 September 21, Janice Castro, “With Friends Like These ...”, in Time

   "I'm gonna hire me a lawyer," he said. "A real junkyard dog."

   2004, Peter Maravelis, San Francisco Noir, →ISBN, page 50

3. A hot dog laden with toppings, such as onions, pineapple, or chili.