It is really hard to tell which animal is the most poisonous in the world. The one that has the most toxic chemicals? The one that kills the biggest amount of people a year? Or maybe the one with the biggest amount of poison?
First of all, I have to admit that the title is a bit incorrect, because there is a difference between poisonous and venomous animals. A poisonous animal carries harmful chemicals called toxins primarily used for self defense. Therefore venomous animals deliver their toxins by stinging, stabbing, or biting. So poisonous animals are passive killers, while venomous animals are active killers.
Nevertheless, theory aside, they are all really dangerous. So look really closely at each photo, cause next time you meet them can be the last thing you ever see.