Here in Oakland (da hood), a "beware of dog" sign says "my dog will eat you so don't try to rob me."

At the apartment my dad lived in, we were pretty high up, where in case of emergency help would come through the window, we had dogs and several cockatiels at the time and they sent us a little sticker that says

"rescue us,too!

______dog(s) _____cat(s) other ___________"

I think i will put a little sign on the bp cage that says "non venemous harmless ball python " just in case...