This species is common enough throughout Sri Lanka that when I saw my first one, which was some distance off the trail and a couple of meters off the ground, my guide decided that we shouldn't bother to try to wrangle it for a decent photograph, since we would no doubt see many more.

Sure enough, we found this beautiful specimen the next night, in ambush position close to the ground.

They vary quite a bit in color and pattern. This one is almost patternless and extremely yellow.

Here's another in head-down ambush position, again fairly yellow, but much more patterned than the previously pictured one.

Intermittent heavy rain brought out a lot of snakes the following night. Here's a trio of youngsters.