The animal responsible for the most human deaths worldwide is the mosquito. Mosquitoes carry parasites that spread malaria, a disease that kills roughly two million people every year.
Mosquitoes may be the deadliest animal on the planet, but there are numerous other animals that cause human fatalities. Animals like the tsetse fly, snakes, scorpions, and deer are all responsible for causing many human deaths each year.
Historians and other scientists would argue that humans are the animals most responsible for human deaths each year. However, the number of humans who die at the hands of other people varies greatly depending on things, such as crimes committed and wars being fought.
Other dangerous animals include tigers, which have killed more humans that any other big cat, as well as bees, bears, and even cows.