Unexpectedly Deadly Animals

The animal kingdom is filled with dangerous creatures. The obvious ones are the predators – big cats, sharks, crocodilians – but there are other, more inconspicuous deadly animals. They may be small, cute, or otherwise appear completely harmless, but contain unsuspected deadly poisons or tendencies. Many are defenses against predators or are reactions to being threatened.

Kayan slow loris

Slow lorises are small, undeniably cute primates with large round eyes that, as their name implies, move very slowly. There are several species all of which are considered either Endangered or Vulnerable. They have experienced recent popularity in the exotic pet trade due to videos of them going viral on the internet. Unbeknownst to many, the Kayan slow loris (Nycticebus kayan) has a venomous bite. They are not highly inclined to bite though. The Kayan slow loris is tiny, less than a foot long and weighing less than a pound. Compared to other slow lorises, the Kayan has highly contrasting facial markings with dark rings around their eyes. The toxins are made near their elbows, and the animals lick their elbows to mix it with saliva, which will activate the poison. They will then lick their babies to protect them from predators and will bite when being attacked or when frightened. 


The cassowary (Casuarius casuarius) is considered by many to be the world’s most dangerous bird. At a glance they look like a goofy ostrich. They are a large, Australian flightless bird with a featherless blue neck, yellow head, brown helmet, and red waddles on their neck. They can live 40 to 50 years, reach heights of 6.5 feet, and inhabit swamps and forests. They are also extremely territorial and aggressive. Their strong legs are armed with three toes, each with a four-inch claw that they do not hesitate to use against predators and unsuspecting humans that get too close.

Giant anteater

Giant anteaters (Myrmecophaga tridactyla) eat ants and termites, which they find by smell because they have very poor eyesight. They do not even have teeth and are what is known as edentate animals. What they do have though are large sharp claws, up to 4 inches long. They mainly use their claws to dig up anthills and are known to be not at all aggressive. If cornered and frightened though, the 7 foot long animal with rear up on its hind legs, using its thick tail for balance, and will use its digging claws in defense. They have been known to fight off jaguars and can easily cause severe injury to humans. 

Leopard Seal

Most encounters that seals have with humans end peacefully. Seals are far more interested in hunting penguins and fish, but are known to be extremely curious about any humans wandering into their domain. They have been known to follow and, more or less, stalk people they encounter, seeming to be playful. The leopard seal (Hydrurga leptonyx) is a spotted seal reaching up to 13 feet and 990 pounds. In 2003, a scientist in Antarctica was drowned by a leopard seal that dragged her down when she was snorkeling. The attack was unprecedented, but showed that the seals do have the capability to be deadly. As human activity continues to increase in their habitat it is likely that the seals will actually prove to be more dangerous if they begin to see humans as a threat. Little is known about the solitary seals and their stalking behavior might actually be determining if a person can be a food source. They have also been known to attack smaller species of seal and the young of other seals, so cases of mistaken identity could occur as well with divers. It is also a possibility that the seal may have been attempting to play with the incident occurred. Their size and strength, if they see fit to use it, makes them easily deadly even if they do not intend to be.


Very few mammals produce venom. Along with the Kayan slow loris, the platypus (Ornithorhynchus anatinus) is another. Platypus are typically thought of as small, odd, harmless creatures, and only the males produce this toxin, which will cause excruciating pain, rapid swelling, along with hyperalgesia in humans. It is capable of killing smaller animals such as dogs as well as small children, but the purpose is not self-defense nor capturing prey. It is actually used during mating season to show dominance over other males by paralyzing them. The venom is released from spurs located on the hind legs of the animals. Interestingly, it is very similar to venom produced by some species of reptiles.