Paypal is safe in that the seller won't get any of your personal information (bank account/credit card numbers/etc.) And it does give you a paper trail to prove that you sent money to this guy. But it doesn't completely protect you from getting scammed. You will have the ability to report it, and file a police report, so chances are you should be able to have something done if the worst happens.

My biggest fear would be if this guy knows how to properly ship a live reptile. Not only are there regulations that need to be followed, but if shipped improperly you could have a dead snake. (but that isn't as likely this time of year) If you get a dead snake I doubt that you will have any legal backup, unless you get this guy to guarantee you a live arrival in writing