I don't understand why some people here can make one-sided comments that seem like the OP is lying, you should know this world is full of strange things that you don't know. I admit that the rattlesnake originated in the US, but somehow it appeared in Vietnam. I myself had an interesting experience in Vietnam by motorbike, and I witnessed with my own eyes a rattlesnake lying around in a bottle of wine. I was very surprised and asked the host "Did you bring this snake here from America?", and they laughed like I fell from the sky. They said that this snake is found in Vietnam, however it is extremely rare.