Ophiophagus hannah - is the world's longest venomous snake. The king cobra averages at 3 to 4 m (9.8 to 13 ft) and longest specimen are up to 5.7 m (18.8 ft). This snake is found predominantly in forests from India through Southeast Asia. The king cobra is by far not the most venomous snake - on the Australian Venom and Toxins database the king cobra just takes the 18th place. However after a bite the mortality rate is very high since the snake injects a huge amount of venom and death may arrive as early as 30 minutes. Keep in mind, venoms and poisons are different, e.g. it is harmless to drink snake venom as long as there are no lacerations inside the mouth or digestive tract.