Hydrophis brookii
Range
Indian Ocean (Malaysia, Vietnam, western Indonesia) and the Gulf of Thailand; also a freshwater lake in Thailand
Brooke's sea snake is a venomous sea snake in the subfamily Hydrophiinae of the family Elapidae, native to bodies of water in Southeast Asia. It is found in the Indian Ocean (Malaysia, Vietnam, western Indonesia including Sumatra, Java and Kalimantan) and the Gulf of Thailand, and also in a freshwater lake in Thailand (Wikipedia, general species account).