The most deadly ­animal in the world is the mosquito. It might seem impossible that something so miniscule can kill so many people, but it's true. Mosquito bites result in the deaths of more than 1 million people every year [source: WHO]. The majority of these deaths are due to malaria. The World Health Organization estimates that between 300 and 500 million cases of malaria occur each year -- and a child dies from malaria every 30 seconds [source: WHO].