Title with thanks to Mr. Scarry.

There are a lot of creatures out there called “worm,” mainly due to Linnaeus’ and Lamarck’s taxon for non-arthropod invertebrate animals stemming from the Old English “wyrm.” “Worm” has been used to describe everything from larvae to the amphibian caecilian to dragons.

Worms vary greatly in size, from microscopic lengths to 180 feet for a marine nemertean worm. Free-living worms can live on land or underwater—both salt and fresh—and a large portion burrows. The rest of the worm types are parasitic, living in the bodies of other animals. Ecologically, worms form an important link in most food chains. Technically, almost all worms are decomposers of one form or another.

Platyhelminthes

These are the flatworms—simple, unsegmented, soft-bodied animals. They have no body cavity, and no circulatory or respiratory organs. Although there is a group of non-parasitic flatworms called turbellarians… we’re more interested in the parasitic ones.

But What about the Penis Fencing?

Oh yeah.

Turbellaria are most free-living and range from 1 mm to 24 inches in length. Most live on land as predators and scavengers, living in leaf litter and only coming out at night. Some use cilia for motion, mostly aquatic species, and others use a muscular system to creep or swim. Nearly all turbellarians are hermaphroditic and fertilize eggs internally by copulating. However, then there are those that mate by penis fencing, something that should definitely be included in a game in some manner or another.

These flatworms fence using two-headed daggerlike penises and battle each other viciously to see which one can stab the other; the winner becomes the father and the loser, who is fertilized, becomes the mother.

Nope. Not kidding. Now back to the parasites.

Oh, For the Love of Everything Unholy, Why!?

Because some flatworms do enormous damage to humans and their livestock due to inappropriately cooked or raw food and poorly designed water supply and irrigation projects. It should be a given that anywhere the player characters go in any historically related RPG, they’re going to have run-ins with parasites. Heck, even today, schistosomiasis is thought to be the second most devastating disease caused by parasites, surpassed only by malaria, with estimates of 200 million infected people over 74 countries. It was estimated in 2000 that 48 million people were infected with tapeworms of either the beef or pork variety. My dear cousin last year got a colon cleansing and had the remains of a tapeworm drop out the next day. There isn’t anything rare about worm infections and likely anyone that goes traipsing across the countryside as much as these PCs do is likely to pick up a parasite or twenty.

The Tapeworms

These critters live in the digestive tracts of vertebrates as adults, and often in the bodies of various animals as juveniles. The beef tapeworm can grow to be 12 m or 40 ft in length, but others can get even longer…upwards to 100 ft in length.

Thankfully, they do not penis fence.

Live tapeworms are sometimes ingested by consuming undercooked food. Many larvae tapeworms can cause as many problems as infestation by an adult. The most common type of tapeworms involved in human infection are the pork tapeworm, the beef tapeworm, the fish tapeworm, and the dwarf tapeworm. Tome people experience upper abdominal discomfort, diarrhea, and loss of appetite but most people experience no symptoms at all. The fish tapeworm can sometimes cause anemia. Most people don’t realize they have a tapeworm until they pass the white wormlike segments in their stool, especially if a segment is moving. Rarely a tapeworm can cause a bowel obstruction and even more rarely pork tapeworm larvae can migrate to the brain and cause seizures, but it can take years before a patient has those symptoms.

Most tapeworm infections occur in areas of inadequate hygiene, as reinfection occurs readily when the eggs (deposited in stool) are reingested.

In ancient times there were plenty of anthelmintic herbs and preparations to kill and expel worms; however, in a sorcery realm where healing potions are a dime a dozen, figure they’re just as effective and sloughing out parasites.

Digenea (Flukes)

The digenea subphylum has about 6,000 species in it, of which only 12 are infectious to humans. Some of those infectious species, make up some of the most important disease infecting humans, afflicting 200 million people. Most common are the Schistosomes which infect humans when they swim in areas of infected snails. The worms penetrate the skin and enter the circulatory system. Currently they are endemic in Africa, South America, the Caribbean, the Middle East, China, East Asia, and the Philippines.

The rest are all non-Schistosomes that infect people when they ingest cysts on plants or undercooked animal flesh. Most inhabit the gastrointestinal tract, but some can infect other regions of the body.

Giant Intestinal Flukes: From snails to edible plants to humans. Usually asymptomatic, although can cause pain, diarrhea, and allergic reaction. Found in Asia, India.

Heterophyes Fluke: Infection from fish. Usually asymptomatic but can cause cramps and diarrhea. The heart and brain can be infected. Found in Asia, Eastern Europe, Egypt, Middle East,

Metagonimus Fluke: Infections through trout or carp. Found in Siberia.

Gastrodiscoides Fluke: Infections through plants in India, Vietnam, Philippines.

Chinese Liver Fluke: Third most prevalent parasitic worm infection in the world. Infection usually through fish, found most often in East Asia and North America. Common Liver Fluke: Distributed worldwide. Usually infection is through plants. Found in North, South, and Central America.

Lung Fluke: Passed through crabs and crayfish throughout Asia. One of the few prevalent lung flukes and the eggs can also be passed through saliva. Causes fever, bad cough, bronchitis, and blood in sputum, rather like tuberculosis; can move to spinal cord and cause paralysis or to heart and cause failure. In Asia, an estimated 80% of crabs contain the pathogen.

Monogenea

These flatworms mostly infect fish (although one parasitizes the eyes of hippos) as ectoparasites (skin only). They attach using hooks and causing massive fish infections.

Although these worms are not really important to humans, for roleplaying games the concept of parasites that use HOOKS to attach to creatures—especially when there are so many interesting monsters to attach to—may be useful.

Nematodes

These are the roundworms and of the 28,000 species described, 16,000 species are parasitic. Nematodes are adapted to every environment from the polar regions to the tropics. The smallest are microscopic, while free-living nematodes can get to sizes of 5 cm. Some parasites can get very big. Most nematode species are dioecious (Separate male and female individuals). The parasitic species cause some of the most common livestock and human sicknesses of the world.

Ascarids: Giant intestinal roundworms. Typically infect pigs and humans in tropical areas with poor sanitation. Up to 35 cm in length, causing bloody sputum, fever, cough, vomiting (worms), liver abcesses, and death by pulmonary eosinophilia. There is a lung phase and then an intestinal phase. Anthelmenthics are given to starve the worm out (most anthelminthics prevent sugar from reaching the worm), but blockage of the colon or pancreas may require surgical removal.

Filarias: Parasitic roundworms caused by a mosquito vector. It causes lymphatic filariasis, affecting 120 million people primarily in Africa, South America, and other tropical areas. If left untreated it can cause elephantiasis—edema and thickening of the skin. There is no vaccine. The disease has been known for thousands of years; even Greek and Roman writers talked about the disease, believing it came from elephants. It wasn’t until the 1800s that a connection was made to a parasite. During the early slave trade the filariasis infections were prominent in South Carolina until its abrupt disappearance in the 1920s.

Hookworms: Parasites that living in the small intestines of mammals, two species of which usually infect humans. One, called the Old World Hookworm, infects people, cats, and dogs in southern Europe, north Africa, China, India, Southeast Asia, and some parts of the southern US, the Caribbean, and South America. The other, called the New World Hookworm, was first discovered in Brazil and then in Texas. Later it was found indigenous to Africa, China, southwest Pacific Islands, India, and Southeast Asia. Transmission is caused by contact with soil infected with larvae. Infections are generally asymptomatic, with some abdominal pain and lethargy. Only heavy infestation can cause anemia. Anthelmintic medicines are effective. Education, improved sanitation, and wearing shoes help prevent infections.

Pinworms: Pinworms are also called threadworms or seatworms. Common in children, pinworm infections are called enterobiasis. Pinworms are distributed worldwide and is the most common helminth infection in the United States and Western Europe. The overall incidence rate in the US is more than 11 percent. After the eggs are deposited near the anus of a host, they are easily distributed. The only symptom most people have is itching of the anal area, although children can suffer weight and insomnia. Medicine kills the parasites, but not the eggs, and reinfection is common.

Whipworms: Can grow to 2 inches long and can live up to five years. The eggs are deposited in feces and end up in soil, causing new infestations when infected foods such as beans, rice, or various grains are eaten. Distribution of parasitic whipworms occur worldwide, with an estimated one billion people infected. It is chiefly tropical and usually found in Asia, then Africa and South America. Light infestations are asymptomatic but heavier infestations can cause bloody diarrhea, anemia, or prolapsed rectum. Treatment using medicines wipes out the helminthes.

Trichinella: Occurring in rats, pigs, bears, and humans, trichinosis is also known as pork worm due to the prevalence of infections from undercooked pork products. They are the smallest parasitic nematodes and are unique in that they encapsulate or cocoon in the muscle tissue to be eaten. This migration and encapsulation of the larvae can cause nausea, vomiting, sweating, and diarrhea. Five to seven days after the appearance of symptoms, facial edema and fever may occur. After 10 days, intense muscular pain, difficulty breathing, weakening of pulse and blood pressure, heart damage and various nervous disorders may occur, eventually leading to death due to heart failure, respiratory complications or kidney malfunction. In recent times the amount of infections and illness from these parasites has been reduced greatly.

Other roundworm parasites: The Baylisascaris: This roundworm is most often seen in wild animals, but can infect humans. Host species include raccoons, European and American, badgers, bears, skunks, fishers, martens, and marmots. Heartworm is a nematode that attacks cats and dogs. Another type is the most prevalent infectious agents in sheep, causing great economic damage all around the world. Other nematodes parasitize insects, plants, and trees.

So What Are the Benefits of Parasitic Worms?

Helminthic Therapy. Hey, you asked. This is the treatment of autoimmune diseases and immune disorders by means of deliberately infestation with a helminth, such as a hookworm or whipworm. Helminthic infection has emerged as one possible explanation for the low incidence of autoimmune diseases and allergies in less-developed countries. It’s being used to treat Crohn’s disease, ulcerative colitis, inflammatory bowel disease, multiple sclerosis, asthma, eczema, dermatitis, hay fever, and food allergies.

So if you infect your players with some sort of parasite and they argue, use this in your argument.

Also, some nematodes may cause crop and livestock problems, but there are some that kill garden pests and those are promoted by most gardeners. This is not as cool as using worms for food or profit.

Speaking of Food and Profit, and Terror….

Sipuncula

Sipuncula are bilaterally symmetrical, unsegmented marine worms, also called peanut worms. Typically less than 10 cm long, although some can triple that, they are relatively common and live in the shallows. They are collected to make sipunculid worm jelly. This is, of course, a delicacy in the Fujian Province of China. They are collected, cleaned of their innards, and eaten. They are also dried as a seafood product.

Acanthocephala

A small group of strange little water-worms, usually yellow, almost all parasitic, that have a number of hosts, including invertebrates, fish, amphibians, birds, and mammals. Called thorny- or spiny-headed worms, they are known for a little process called “brain-jacking.” The worm parasitizes a crustacean and makes the critter desire the light. This crustacean will go so far as to step out onto a rock’s surface and wait to be eaten.

Nemertea

These worms are also known as proboscis or Ribbon worms and while most are less than 20 cm long, some species can top 54 meters, making them the longest creatures on earth. Most live in marine environments although there are freshwater species and a few that live in moist soil on land. They’ve been noted since the 1500s and are often used as fish bait.

Annelids

These are your classy earthworms and other segmented worms, such as ragworms and leeches. They are found in most marine environments, in freshwater, and in most terrestrial areas. The burrowing worms contribute to the soil’s fertility. Earthworms are a major part of many animals’ diets. Marine annelids account for over one-third of bottom-dwelling species in coral reefs and intertidal zones and contribute by increasing oxygen and water penetration in the ocean floor’s sediment. These water annelids are studied by scientists to monitor oxygen levels, salinity, and pollution levels in fresh- and saltwater environs.

Anglers often use worms for bait to catch fish and ragworms are commercially used in aquaculture and for fish farm bait. And earthworms are sold all over the world to help garden soil. It was estimated in 1980 the Canadian export value of worms was $13 million and an American retail value of $54 million.

Leeches have been used in blood-letting at least since the Chinese documented it in 30CE. India reported using leaches in 200 AD, and the Romans in 50 AD. Leeches became so popular that some species became endangered. Nowadays leeches are used in microsurgery, and their saliva provides anti-inflammatory compounds and anticoagulants, which can also stop tumors from spreading. Can’t just use any leech, however; some transmit flagellates that cause disease.

And, of course, you can eat them. The rear end of the Palolo worm detaches in order to spawn at the surface and the local Samoans find this to be a delicacy. Earthworms help make noke, a culinary dish made by the Maoris.

Worms are Symbolic too

No doubt. Worms are often used to describe putrefaction or corruption. The worm or “wyrm” was a nasty draconic beast and represented the Old English description of Satan. The Viking stories are full of worms. Worms still represent corruption, in the form of malicious internet software.

Game Stuff

It is said Cleopatra made it illegal to kill an earthworm because of their contribution to agriculture. Although this story is in question, it might be fun to throw in a society where a critter is illegal to kill due to a contribution the PCs have no care about.

If you haven’t figured out how to incorporate penis fencing into your game, might I suggest you catch the PCs off-guard with a mating ritual between two gigantic sandworms in a desert. It could also be used by certain creatures that are more humanoid in appearance. Perhaps a succubus like creature whose idea of mating is to perform this ritual…loser becomes the “mom?” That might be a contest….

Parasites. There was a conversation over five years ago in rpg.net about a girl coming back from some tropical county and having so many worms in her gut the doctor could hear them as they moved pas each other… said it sounded rather like chirping. If you are so inclined to give a PC enough worms that he or she can hear them chirp, that’s great. Figure that an infection like that will take a healing potion to kill the adults and another a week later to take out the juveniles. Whether or not you want to discuss the proceedings in the toilet, are between you and yours.

Brain-Jacking sounds like a fun idea as well. It’s what the screefice would do, or any other number of creatures. Especially the larvae/juveniles. A lot of these adult monsters seen in their manuals would do well to have a juvenile version that brain-jacked their host and made them go somewhere so the juvenile can move to an adult stage.

That’s enough Nightmarish stuff for one Evening….

Closely related to these groups are the mollusca members, but they are so darn useful to humans and include our favorite cephalopods, so I’m saving them for the next article.