there are three species, all variously called elephant trunk snakes, file snakes, or wart snakes.
This one is Acrochordus javanicus from southeast Asia. The other two are the Arafura file snake A. arafurae of northern Australia and New Guinea, and the little file snake A. granulatus which is found from India to Australia.
For some reason I tend to call javanicus an elephant trunk snake, but the other two species I always call file snakes. I don't know why.