The most deadly animal in the world is the mosquito, which causes around one million deaths per year by spreading diseases such as malaria, dengue fever, and Zika virus. Other animals that are responsible for a significant number of human deaths include humans themselves, with homicides accounting for an estimated 400,000 deaths per year. Here is a list of the top 10 deadliest animals to humans, according to various sources:

1. Mosquitoes - kills 725,000 per year
2. Humans (homicides only) - kills 400,000 humans per year
3. Snakes - kills 50,000 per year
4. Dogs - kills 25,000 per year
5. Tsetse flies - kills 10,000 per year
6. Assassin bugs - kills 10,000 per year
7. Freshwater snails - kills 10,000 per year
8. Scorpions - kills 3,250 per year
9. Ascaris roundworms - kills 2,500 per year
10. Tapeworms - kills 2,000 per year

Its worth noting that different lists have varying criteria and definitions, so lists from different sources may disagree and can be contentious.