It was Harley's job to see how stray dogs react to cats.
Officials at the Humane Society's animal shelter in Albuquerque, New Mexico, say Harley has confronted more than 700 dogs over the years.
The shelter's Sam Blankenship describes the 12-year-old cat as "very brave" and "looks death in the eye every day."
Harley is now up for adoption.
Shelter officials say they're looking for a new test feline.