The Nile crocodile is the most aggressive animal in the world mostly because it considers humans a “regular part of its diet” according to a-z-animals.com. The animal can weigh up to 1,650 pounds and can be found in 26 countries in sub-Saharan Africa.
Snakes are, in many senses, cold-blooded killers. Five million snakebites occur around the world every year, with more than 50,000 fatalities — making snakes the third-deadliest animal after mosquitoes and humans.
These explosions generate beams of high-energy radiation, called gamma-ray bursts (GRBs), which are considered by astronomers to be the most powerful thing in the universe. What's more, these GRBs could be killing our chances of ever discovering life on other planets.
Scientists sometimes call Amur leopards the “silent killer” since they're so good at sneaking up on prey.
Toughest Animal for Brute Strength:
Scientists believe gorillas (Gorilla gorilla) have 20 times the strength of an adult man. These animals can be four to six feet tall and weigh up to 440 pounds. Gorillas live in the forests of Africa, specifically the Congo Basin.
Animals with no natural predators are called apex predators, because they sit at the top (or apex) of the food chain. The list is indefinite, but it includes lions, grizzly bears, crocodiles, giant constrictor snakes, wolves, sharks, electric eels, giant jellyfish, killer whales, polar bears, and arguably, humans.
Four species of sharks account for the vast majority of fatal attacks on humans: the bull shark, tiger shark, oceanic whitetip shark and the great white shark.
Animals unquestionably kill members of their species, all the time. Male lions slaughter all the cubs when they join a new pride; rival ant colonies of the same species fight bloody wars; chimpanzees have been shown to kill each other at similar per capita rates to humans. Does any of this count as murder?
While larger animals like sharks or hippos may seem a likely culprit, the animal that kills the most humans per year is actually the mosquito.
Rottnest Island is known worldwide to be the home of the happiest animal on Earth – the Quokka (Setonix brachyurus). Close relatives of Wallabies, these tiny animals are found all over Rottnest Island, where their survival is largely attributed to the exclusion of any natural predators.
The mosquito is responsible for more deaths worldwide than wild animal attacks. The mosquito is the silent predator who strikes and leaves disease in its wake. For this reason alone the mosquito should make us all fearful for it gives no warning of it's oncoming bite.
Do lions have predators? No predators hunt lions to eat them; however, they do have a few natural enemies, such as hyenas and cheetahs. Hyenas compete with lions for food and often try to steal their kills.
The 'immortal' jellyfish, Turritopsis dohrnii
To date, there's only one species that has been called 'biologically immortal': the jellyfish Turritopsis dohrnii.
The honey badger has been called the world's most fearless animal because it doesn't hesitate to attack animals much larger than itself- even lions and crocodiles! Honey badgers are found in arid grasslands and savannahs and even rainforests.
Watch: Dracula ant's killer bite makes it the fastest animal on Earth. The Dracula ant can strike 5,000 times faster than the blink of an eye, beating the old equivalent speed record by a factor of three. The jaw of a Dracula ant goes from 0 to 200 miles per hour in 0.000015 seconds.
The Mute Swan, however, is quiet but fierce and males are extremely territorial during the breeding season. It's considered to be one of the most dangerous birds in the world. If you think male geese are bad enough, you don't want to know what it's like for male mute swans to beat them.
Snails, jellyfish slugs, and worms are some examples of animals that do not produce sound to communicate.
Skunks are shy and docile animals that are easily startled — and you definitely don't want to startle one. Preferring to to live alone, skunks are usually only social during mating season. Several females may also share a den during the colder months to stay warm.
In terms of the number of humans killed every year, mosquitos by far hold the record, being responsible for between 725,000 and 1,000,000 deaths annually.
Man's best friend is actually one of the world's deadliest mammals. Worldwide, dogs are responsible for about 25,000 human deaths from rabies each year resulting from maulings and bites.
According to our best models of the evolution of the universe, the most likely scenario is what's called the Big Freeze. If dark energy keeps accelerating the expansion of the universe forever – and calculations suggest that it will – then the cosmos is in for a slow death that's drawn out for a googol years.