Surviving the bite of a blue-ringed octopus can be a harrowing experience. Ten minutes after you're bitten, your esophagus goes numb and you are unable to speak or breathe, but if you're hooked up to a ventilator in time, you will survive. There is no antidote to this octopus' bite, but after about 15 hours the paralysis will subside.
The black mamba is an aggressive snake that mostly resides in Africa. Although their initial bite causes little damage, victims experience paralysis and breathing troubles and within six to seven hours. Death may occur if the bite is not treated.
The pufferfish has many layers of protection for itself. It has the ability to rapidly take in water, which causes its body to expand to four times its normal size. The pufferfish also has a very foul taste to most other predators, not to mention that it contains the poison tetrodotoxin that is 1,200 times more poisonous to humans than cyanide.
The inland taipan resides mostly in the desert climates of Australia. Even though they are considered one of the most poisonous snakes in the world, they've never caused a single human fatality, which is mostly due to their remote habitat.
Black widow spiders can be identified by the red hourglass that they have on their abdomens. They are very poisonous spiders and their venom is reported to be 15 times more dangerous to humans than a rattlesnake's bite.
The box jellyfish is widely considered the most venomous animal in the world. The venom in their delicate tentacles attacks the heart, nervous system and skin of their prey and is described as being incredibly painful. According to Science Based Life, box jellyfishes have accounted for over 5,000 deaths since the 1950s.