Pup of unknown origin (4)

I believe the answer is:

mutt

(Other definitions for mutt that I've seen before include "Mongrel - fool" , "Setter perhaps" , "Thematic type [DOG]" , "Mongrel dog - foolish person" , "Chump" .)

I've seen this clue in the LA Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.