In reply to Carol B:
Sounds like some sort of whip snake to me (a constrictor, harmless). If it was really black, then don't think it would be a Montpellier. I see them regularly where I live (Montpellier and whip snakes) along with a fairly venomous variety of viper. If it was a Montpellier then it would still be fairly harmless as, whilst venomous, it's fangs are positioned well back in it's mouth making it difficult to inject the venom, and the venom isn't supposed to be very toxic to humans anyway.