Dental details
Mambas are venomous elapids, or "fixed-front-fang" snakes. This means that their fangs are in the front of their mouths and are attached to their upper jaws. Elapids can't fold their fangs out of the way when they close their mouths like vipers can, so their fangs must be fairly short. Otherwise, they'd poke through the snakes' lower jaws.
Upstanding snakesCobras, like their close relatives the mambas, can move forward while keeping their heads and a portion of their bodies raised above the ground.
Sea serpentHardwicke's sea snake is an elapid that can kill a person with one bite. Fishermen are the most frequent bite victims, because these snakes often get caught in fishing nets.
Pretty and poisonousCoral snakes are elapids that live in North and South America.