Ophiophagus hannah

The king cobra is the world's longest venomous snake, growing up to 18 feet tall. It lives in forests across South and Southeast Asia, and its bite can be deadly even to large animals. Never approach one. Stay far away and find an adult right away.
The king cobra is the only snake in the world that builds an actual nest for its eggs, and the mother guards it fiercely until the babies hatch.
This one is venomous, which means it can put venom into you with a bite or a sting. Never touch it, and never try to move it yourself.
Always ask a grown-up before you touch any animal or plant. If something bites or stings you, tell an adult right away.
Source: Smithsonian's National Zoo
Read more about the king cobra at Wikipedia.