Since when did mosquitoes get reclassified as animals? They are insects that are passing on a disease. an animal kills with it’s claws and teeth. And then eats you while you may still be alive. The OP asked for an animal that killed people, not a disease or obesity.
I’m now thinking wolves since they have a wide range of habits worldwide.
You might want to take another look at what the definition of an animal is.
Hint: includes insects.
It was back on the day in which the words “animal”, “insect”, and “mosquito” were all given their definitions.
Despite the fear there aren’t that many recorded instances of people being killed by wolves.
“The country with the most extensive historical records is France, where nearly 7,600 fatal attacks were documented in from 1200–1920.”
I’m not good at maths, but that looks like a little over ten per year in that time period. Hippos probably did better.
Then he’s completely wrong. The WHO data I posted showed 1.6 million deaths per year by AIDS. Humans carry the AIDS virus. If he’s counting mosquitos carrying diseases, he should count humans giving other humans AIDS.
Yes, I know the dictionary definition that every living thing is an animal, but then animals get split up into subcategories of insects, bacteria, reptiles and such. Most people don’t commonly call insects animals in everyday conversation. If the OP would clarify what he was looking for . . .
I’ve never heard of anyone who didn’t consider mosquitos to be animals in everyday conversation or conversations that occur years apart. Nor are all living things animals. The only ambiguity in the OP is whether the animal directlyy kills the person as opposed to passing on a disease.
We can just decide that ourselves eh? Ok, it has to be direct, not just carrying a disease.
I’ll stick to cows.
1.4 billion people worldwide are obese.
“According to the McDonald’s Corporation website (as of June 2012), McDonald’s has, “More than 33,000 restaurants around the world in 118 countries. In the United States, there are more than 14,000 restaurants…” In 2007 there were 30,000 restaurants in 119 countries so in the intervening years, one McDonald’s country was lost.”
I doubt any dictionary says any living thing is an animal. For my part, it seems obvious to me that mosquitoes would be included under “animals”.
OK, I’m being Mr. Pedantry Personified here, but since the OP used the term ‘animal’ in the singular I’m putting forward The Champawat Tigress, thought to be responsible for killing about 430 people in the early Twentieth century.
This is entirely incorrect. For example, plants are living things but not animals.
The mosquito, I’d guess.
Add 300 more deaths to the death-by-cow total:
The OP asks “which animal has killed the most humans?,” not which animal is responsible for the most human deaths. There’s a difference.
Mosquitos don’t kill humans. They deliver parasites that kill humans.
Cows don’t kill humans in any appreciable numbers. Even if obesity is considered a cause of death (a debatable point), and even if eating beef is a significant cause of obesity (a debatable point), that’s still not a case of cows killing humans. Humans killing themselves, maybe, but not cows killing humans.
No - bacteria are not animals. Protozoa are not animals. Fungi are not animals. Plants and algae, again not animals. Sponges on the other hand are animals - what they aren’t are vertebrates.
Now I’ll grant that most people probably don’t think of things like tunicates and sponges as animals ( though they are ), but it seems to me most people do consider insects animals even by the loosest definition of the word. I’m sure I did when I was a little kid - ‘the birds and the bees’ and all that. But regardless we’re in GQ and don’t have to adhere to foolish lay definitions ;).
But you wanted to limit the discussion to just vertebrate animals, well then Russell’s Viper might be the most prolific killer, though it has some serious competition from the likes of Saw-Scaled Vipers ( which has the distinction of being both among the Big Four as well as killing in the ME/NA ), Puff Adders and the Indian Cobra.
If you look at the link you’ll see that he did indeed include humans.
I was going to mention that malaria is caused by protozoa, which at one time were considered animals (or at least there were in 7th grade science - not sure about formal taxonomy) but are now in a different kingdom.
I’m not sure of bacteria (and almost positive viruses) were never considered animals.
Brian
According to this guy, snakes are #4 behind humans, mosquitos, and tsetse flies which would be carriers.
Since the OP is new and hasn’t come back to clarify his question I’d say this is more likely what he had in mind; cause I’m a freaking mind reader even if I anit no good at dictionary meanings. 
I was thinking more in line of what people think of when they think “kill that damn thing before it kills us right this very minute” us sort of animal. Nasty little buggers snakes. And there venom is home grown, not some disease that is tagging along with them. Perhaps bees would also qualify since I now allow them in my animal kingdom and will welcome them onto my Ark. 
Oh, and welcome to the board Cardboard! It’s generally considered nice (but not necessary) to participate in the threads you create. but no harm.
There is also the ambiguity of what ‘outside of humans’ means. In one sense cows won’t qualify because they’re killing us when they’re inside of us. Mrs. O’Leary’s cow and a few stampedes don’t kill many humans from the outside.
And of course, inside of a dog it’s too dark to read.