Hi there! From the photo the mass does appear to be a benign papilloma (wart). That being said, it is not easy to tell 100% from a photo. I would still recommend you take Jack to your vet for an exam just to be on the safe side. I do not think it's an emergency situation. While you are waiting to take him in for his exam be sure to monitor the mass closely for any drastic changes in shape or size.