Isn't nature wonderful!
I see all sorts of interesting sights on my walks around Tarascon!
If my research is right this is a Western Whip snake or Couleuvre Vert et Jaune, recognisable by its prominent eyes with round pupils, transversal dashes on the body changing to longitudinal towards the tail. It can grow up to 2 mtrs. long and is non-venimous but care should be taken if you do come across one. They bite and are very quick and agile!