Well, there are many species of vipers, but on average, they are the fastest. The fastest striking snake in the world is the puff adder. People here are saying mambas are fast strikers. Mambas are elapids, like cobras. They aren't vipers. Elapids tend to be much faster moving snakes than vipers, but much slower strikers. I would not list a mamba with fast striking snakes. But their overall speed on ground and the toxicity of their venom is what makes them dangerous. Look at the snake charmers. They use cobras because they strike very slowly. You don't see them doing it with any vipers such as rattlesnakes! Edward D, the inland taipan has the strongest venom of any land dwelling snake, not the black mamba or any other mamba for that matter.