Yes and no. Snakes are very common in Vietnam, and there are many different kinds that are venomous. I don't know the statistics of snakes biting people, but I would imagine it's not a lot. But I could be wrong.
I wouldn't worry so much about octopuses though. They're relegated to the ocean, so you probably won't encounter them all to often anyway. :)
Snakes are pretty common there in Vietnam. What you can do is remain calm if you see one and just walk away. There's is more to Vietnam than just snakes. The place is amazing why let a small creature stop you from experiencing an amazing adventure to a wonderful land.
