This list would not be complete if we failed to include humans on it. As a species, humans murder around just under half a million people every single year.
1. Mosquitoes
Mosquitoes are the smallest creatures on this list, but they are, without doubt, the most deadliest. It has been estimated that mosquitoes transmit diseases such as malaria and dengue fever to around 700 million people each year, resulting in around 660,000 to 1,000,000 deaths.