European cat snake (Telescopus fallax) (Fleischmann, 1831) Ξυλόδροπης,Αγιόφιδο - Cyprus

The European cat snake (Telescopus fallax), also known as the Soosan snake, is a venomous colubrid snake endemic to the Mediterranean and Caucasus regions.
The snake is a venomous species, but it is considered no threat to humans because it is rear-fanged and does not possess the ability to deliver the venom to humans, It can and does, however, use the grooved fangs at the back of its upper jaw to inject venom sufficient to kill its principal prey
The European Cat Snake feeds mainly on geckos and lizards.

[bjornb]

They seems to be either brown or grey in color. Maybe the same characteristic as Vipera Berus when look for its sex? Brown for female and grey for male?