Info: The man in video is researcher at the Amphibians and Reptiles Laboratory at Natal, Rio Grande do Norte. The snake is a Xenodon merremii, not poisonous, can grow over 1.5 meters, found in all South America. The man moved a log and the snake came out doing its natural defensive display, natural when it meets a predator. He used the moment to grab her by the tail, so it could keep doing the movement and he could register it to use in the classrooms and courses about this snake and its behavior.