7 Most Horrifying Parasites on the Planet

Have you encountered any of these?

Parasites are horrible, like proper horrible. From mind-control fungus to worms that swim through your eyeballs. Join us as we vomit our way through 7 of the most horrifying parasites on the planet!



7. Human Bot Fly

Human Bot Fly is one of the most horrifying parasites on the planet.

These things are a nasty breed of fly that have parasitic larvae that burrow into skin to gestate. Firstly, the Bot Fly will capture a mosquito and attach its eggs to its body. The mosquito will then fly off looking for a host to feed on. When the mosquito punctures the skin of the host, the Bot Fly larvae crawl into the wound where they live for up to eight weeks.

A known remedy for a Bot Fly larvae infestation is to cover the entrance to the wound with nail polish so as to suffocate the creepy little bastards. Then you pull them out with tweezers.  I think I just vommed a little in my mouth.

6. Tongue Eating Louse

Tongue Eating Louse is one of the most horrifying parasites on the planet.

This is a parasitic crustacean that eats tongues! Now, before you shut this article down and hide under your bed, luckily this parasite does not affect humans. Known as Cymothoa exigua, the female of the species will enter fish through the gills, moving along to the back of the tongue where it punctures it and feeds off the blood. She’ll sit there at the back of the fish’s mouth feeding on blood until the tongue wastes away and falls off. The parasite will then attach itself to the stub of the tongue and steal food as it enters the fish’s mouth.

Worse still, a male can also enter the fish via the gill where it will mate with the female right there in the fish’s mouth!

5. The Loa loa

The Loa Loa is one of the most horrifying parasites on the planet.

Also known at the African Eye worm, this demonic parasite occupies the subcutaneous layer of human skin, often seen swimming across the eyeball of the infected person.

Transmission occurs when a vector fly bites a human, creating a nice little hole for larvae to enter. Here the larvae mature and wriggle about, often inside the eyeball of the poor host. Once fully mature the worms seek out a member of the opposite sex, if mating is successful the female will release thousands of eggs known as microfilariae which circulate in the host’s bloodstream.

4. Guinea Worm Disease

Guinea Worm Disease is one of the most horrifying parasites on the planet.

This horrible disease occurs when a person drinks water that contains water fleas that are infected with Guinea Worm Larvae. When the fleas hit stomach acid they dissolve, releasing the Guinea Worm Larvae into the intestinal tract. Here they’ll stay for up to one year before migrating through subcutaneous tissue, causing immense pain. Finally the worm arrives at the foot of the infected person where it will piece the skin causing awful, burning blisters. People afflicted with these blisters often find relief in dunking their feet in water which is exactly what the worm is hoping for. The female Guinea Worm will poke its head out of the wound and vomit thousands of embryos into the water so as to repeat the whole terrible cycle.

Female Guinea Worms can grow up to 100 centimetres long. The only way to extract a worm successfully is to slowly, over a period of weeks or months, wrap the worm around a stick. So you turn the stick just a little bit each day, just to pull this demon worm out of the wound. I think I vommed again.

3. Leucochloridium paradoxum

Leucochloridium paradoxum is one of the most horrifying parasites on the planet.

Also known as the Green-Banded Broodsac this parasitic flatworm sounds like something out of Star Craft. Starting its life out in a pile of shit, this worm waits for an unsuspecting snail to feast on the poop. Once inside the snail, the parasite worm makes its way into the eyes of the poor host, transforming them entirely. The eyes of the snail change into two protrusions that resemble caterpillars, making them irresistible to passing birds. The snail is then eaten by the bird and the Green-Banded Broodsac now enters the digestive system of its new host, where it feasts and reproduces. Thousands of eggs are laid inside the bird, which are then pooped out. And there the bird turd awaits an unsuspecting snail, teeming with parasitic worm larvae ready to complete the life cycle.

2. Zombie Fungus

Ophiocordyceps Unilateralis is one of the most horrifying parasites on the planet.

Ophiocordyceps unilateralis is a type of fungi that can infect Camponotini ants. Once the ant is infected the fungi will effectively control the ants mind, ordering it to leave the nest and foraging trails in search of ideal temperatures for the fungi to grow. The mindless zombie ant will bite a leaf on the forest floor and stay there frozen for up 10 days before the fungi tears through the head of the ant to release spores into the air.

Fun fact: This fungus was used as inspiration in Naughty Dog’s survival horror video game The Last of Us.

1. Ascaris

Ascaris is one of the most horrifying parasites on the planet.

Also known as Intestinal Roundworms, these parasitic worms can grow as long as one metre in length and tend to migrate throughout an infected human. Swallowed eggs first hatch inside the intestines of the host, before the larvae move through the bloodstream and into the lungs. Symptoms include nausea, severe coughing and shortness of breath. Often infected people will vomit worms or have them pass out their anus like long wriggly spaghetti.

That’s it. I’m out!