Most of the time, when venom is brought up, the discussion centers on snakes, spiders, jellyfish (king cobras, black widows, and box jellies—oh my!), but the world of venomous wildlife is full of surprises. Below is a sampling of the lesser-known members of the Venom Club: some strange, some beautiful, and some downright draconic.

DUCK-BILLED PLATYPUS

The platypus is famous for being strange, like much of the wildlife in its native Australia. It seems to laugh in the face of Linnaeus, with its bizarre suite of mix-and-match traits: a beaver’s paddle-tail, a birdlike bill, a coating thick fur—and to top it all off, they lay eggs. Today we know that these bizarre traits are a result platypuses being part of the ‘primitive’ line of mammals known as monotremes.

A platypus from above:

There’s one more thing that makes platypuses stand out: they are venomous. Even more unusually, only males are venomous. There are spurs on their hind legs, just above the feet, which can deliver a painful cocktail of toxins. Though excruciating, the venom is not usually fatal. Normally, the spurs lie flat against the leg, but they can be raised as necessary.

The platypus’s venom is a bit of a conundrum. It is not use for hunting purposes, and seems primarily defensive in nature. However, only males have venom glands. Studies have shown that venom production increases during the breeding season, leading biologists to theorize that the venom is primarily used as a weapon in male-male competition.

BLUE-RINGED OCTOPUS

The blue-ringed octopus is a small octopus, found around Australia and in the eastern Indo-Pacific. Mostly a dull brownish-yellow color, it gets its name from striking, electric-blue rings circling the dark ‘eye-spots’ which cover its body. Thanks to octopuses’ ability to control the pigments in their skins, these rings can seem to glow when an individual is excited or aggravated. Of course, blue-ringed octopuses are most remarkable for being the only venomous species of octopus—and they pack a hell of a punch.

A blue-ringed octopus showing off it's blue, blue, electric-blue rings:

They deliver their venom with a bite, which is not painful. Victims may not even notice they’ve been bitten until the symptoms begin to manifest. The toxins in their venom quickly cause motor paralysis and respiratory arrest within moments of exposure, which ultimately results in cardiac arrest from lack of oxygen. There is no available antivenom. Their toxin is created by bacteria which live in the octopus’s salivary glands.

Bites and fatalities are comparatively uncommon, as the animals are not aggressive. Bites typically occur when somebody steps on one or handles one, ignorant of the danger.

(Note: "blue-ringed octopus" applies to a handful of closely-related species in the genus Hapalochlaena)

SHREWS & SOLENODONS

Aside from platypuses, the group of venomous mammals also includes several species of shrew. Shrews are tiny mammalian predators, with overclocked metabolisms and voracious appetites. They look for all the world like long-nosed mice, but are not rodents (order Rodentia), rather they’re members of the order Soricomorpha (“shrew-form”), family Soricidae.

Several species, namely the Eurasian water shrew (Neomys fodiens), northern short-tailed shrew (Blarina brevicauda), southern short-tailed shrew (Blarina carolinensis), and Elliot’s short-tailed shrew (Blarina hylophaga), have toxins in their saliva which they use to subdue prey.

Solenodons look like oversized shrews, with even more pronounce proboscises. They, too, have venom in their saliva, which they deliver via grooves in their lower incisors. Like platypuses, solenodons are generally considered very ‘primitive’ mammals—they likely offer a fair approximation of what mammals at the end of the age of dinosaurs were like.

A solenodon:

KOMODO DRAGON

Until recently, the only well-known venomous lizards were the closely-related gila monster and beaded lizard. The Komodo dragon was famous for being the largest living lizard, a monster of a monitor, with a potent suite of bacteria in its bite that would quickly incapacitate prey. However, in 2009, researchers discovered that Komodo dragons do indeed have venom, which causes a blood pressure, increases bleeding from, and quickly sends prey into shock. Of course, there has been debate in the scientific community.

This Komodo dragon may be hiding venom behind those pebbly lips.

What’s more, research seems to be showing that many species of lizard use venom, counter to prior knowledge. Bryan Fry, a researcher from the University of Melbourne in Australia, has estimated that close to a hundred species of lizard may actually be venomous: quite a long-shot from the two-species paradigm I was taught in my childhood.

I'd like to add a few more to that list.

The appropriately named Shocking Pink Dragon Millipede (Desmoxytes purpurosea) is as strange as its name suggests. Like many poisonous animals, the coloration is a warning - it produces hydrogen cyanide, a famously deadly substance. Here's a photo of this Thai millipede:

Another one that I like is the Sea Wasp (Chironex fleckeri), which is a species of box jellyfish. It is true that many jellyfish are famous for stinging, but few if any can compare to this one. Just a few quick facts:

• the poison can kill a person in 3 minutes if untreated
• one animal has enough poison to kill 60 adults
• it has 60 pale and almost transparent tentacles up to 3 m (10 ft) long 

Here's a photo of this jellyfish, who lives in the waters off southeastern Asia and northern Australia:

Check out a few more below. The Death Stalker Scorpion is a particularly alarming name.