‘I am Nag,’ said the cobra; ‘look, and be afraid!’….But at the bottom of his cold heart, he was afraid. -Kipling It was our last full herping day in Thailand, and so far all of our venomous snakes had been pit vipers (Trimeresurus vogeli), at rest on tree branches over our heads.  This last day we were at Kaeng Krachan National Park, a few hours southwest of Bangkok, and as it was hot and dry we were driving from water hole to water hole, looking for herps out to get a drink or a meal.  The water holes, vaguely square or lozenge-shaped, were man-made, and dug for the park’s elephants and other charismatic wildlife. The abrupt edges of the water…