Dallas Animal Shelter manager Kent Robertson says the man found his missing gray and blue short-haired cat at the shelter, where it had been brought by someone who thought it was a stray.
He blew his stack when told he had to pay a $132 fee to take his cat.
Police say the man returned Monday, loaded his cat into a carrier without paying the fee, and threatened the staff with the baseball bat. No one was injured.
Most people thank shelter workers. Says Robertson: "This was pretty extreme."
The man could be charged with aggravated robbery and aggravated assault.
Police Senior Cpl. Kevin Janse says police have a clue - the man signed the shelter guest book before fleeing.