Not A Cat
Responding “who’s this” to a number who don’t recognize is the standard go to. However, it can be quite frustrating when they don’t easily cooperate to share their identity.
This wrong number seems to be having fun with the receiver. Continually sending photos of their dog in response to being asked to reveal who is on the other end. This situation seems to get the one guy a bit fed up, asking to stop sending pictures of his cat. How rude, that’s not a cat!