The old standby, Wagler's viper, Tropidolaemus wagleri, Thailand.
A decade or so ago, the Wagler’s viper, Tropidolaemus wagleri, once thought to be just a very variable snake species, was determined to actually be a species complex. Researchers have now elevated several of what were long considered simply geographic or color variants of the Wagler’s viper to full species status. This has, of course, rendered the Wagler’s viper, itself, much less variable, but definitely no less interesting.

Besides T. wagleri of Thailand and West Malaysia the genus now contains:

Hutton’s pit viper, T. huttoni (a poorly known species from southern India)

Mindanao pit viper, T. philippinensis (a genetically separable Wagler’s viper lookalike from Mindanao)

Keeled green pit viper. T. subannulatus of the Philippines and Borneo (as described, possibly a species complex)

Broad-banded temple pit viper, T. laticinctus, of Sulawesi.

The alternate name of temple viper (applied to at least 2 of the species) seems to have originated due to the abundance of T. wagleri near the Temple of the Azure Cloud in Malaya.

If you search old literature or Google the species, you will undoubtedly see photos of people, old and young alike, often near the Temple of the Azure Cloud, holding Wagler’s vipers barehandedly. In my opinion this is unwise in the extreme. Admittedly this snake, nocturnal by nature, is relatively placid and reluctant to bite in the daylight hours. They are far less apt to allow indiscriminate handling after dark. It is to the best interests of all herpers (and especially yourself) that you not become an expensive and controversial snakebite statistic.