Up N' Atom (1947)

A very dumb dog is chasing a cat. A smarter dog suggests getting the cat to come to him instead; the dog mounts a parade proclaiming "Be Kind to Cats Week" and encouraging the cat to shake hands with the nearest dog. He does; the dog has a mallet behind his back, but the cat has an endless array of protective hats. The dog then tries a marionette of an attractive female cat to lure the cat to some doors propped up in the woods; again, the cat eludes the dog. Eventually, the smart dog reappears, revealing himself as the cat in a dog costume.

Unfortunately the movie Up N' Atom is not yet available on HBO Max.