The king cobra (Ophiophagus hannah) is the world's largest deadly snake and measures up to 18 feet long (5.4 m), as per the Natural History Museum in London.
When attacked, a king cobra would flare out its "hood," or the skin over its head, using specific ribs and musculature in its neck. According to the Smithsonian Institution, the snake's acute vision enables it to see an approaching person from a distance of around 330 feet (100 meters). Moreover, as per the San Diego Zoo, these snakes can also elevate their heads off the surface, approximately 1/3 of their body length.
Its standout feature is the amount of venom delivered into victims, not the potency of the venom. According to the Fresno Zoo, each bite delivers roughly 7 milliliters (around 0.24 fluid ounce) of venom, and the snake typically attacks with 3 or 4 bites in rapid succession. As per Sean Carroll, a biological researcher at the University of Maryland, a single bite can kill a human in 15 minutes and an adult elephant in just a few hours.