What is the most venomous animal?

The most venomous animal in the world is the box jellyfish; there are multiple species of box jellyfish, some of which are more venomous than others. Some box jellies have enough venom in their stinging tentacles to kill an adult human swimmer before he or she is able to reach the shore.

Individuals who survive a box jelly sting are in for a painful recovery. The toxins contained in this sea animal's venom attacks multiple vital organs and systems, including the skin, heart and nervous system. The box jelly's sting is also painful enough to cause a person to go into shock, which can lead to death by drowning or heart failure.