Desert Worm - Terror of the Empty Quarter

The Desert Worm is a rare breed of gigantic worm. It somehow only lives in the Empty Quarter of the Arabian Peninsula, especially in the deep desert. An ambush predator it feeds when it can, and will pretty much eat anything it can catch.

Basic Information

Anatomy

Like many worms, the desert worm is segmented with a hardened external chitin on the segments. A row of spines run down either side, and are mildly poisonous causing more of an allergic reaction in many species. It's head is wide with two hooked mandibles either side, and if pressed at the centre between them to open the mouth cavity, and swallow reflexes to kick in. These mandibles are modified spines. At the top of the head is a set of five antenna used to sense prey. The two spikes directly below the head are modified, and larger, used for digging into sand and holding itself in place with the head up.
As a worm it is tubular in shape, and its digestive tract runs the whole length of the body. Also the hooked mandibles can be used to stun prey, and strong enough to cut some prey in half. A unique aspect is the chitin it has. Exceptionally durable, it is coloured in bright iridescent colours with multicoloured parts, and an almost metallic sheen to it.

Genetics and Reproduction

They seem to be related to primitive worms found in the Indian Ocean at the depths of it, and they seem to give of pheromones to attract others when they are ready to mate. No-one has ever seen them mate due to their scarcity, and the fact they live in deep desert, and are burrowers by nature.

Growth Rate & Stages

The desert worms grow very slowly, reach adult size (if that is possible when about 2 years old. They are broadly muscular and can grow to be the thickness of a fully grown elephant in thickness if not slightly larger. It sheds it's chitin regularly and rubs itself against the sand of its burrow to remove it. Many locals learn to spot he iridescent particles that accumulates in the sands around its burrow to avoid direct contact. The worm itself if it survives long enough can grow to 10 feet in length or longer, with one being estimated at least 25 feet long in the deep desert.
When they breed only one embryo will survive out of a clutch of about 6, 7 or 8 eggs. The eggs are buried in a patch of wet sand just below the surface and the embryo that can grow quickest will devour the rest for sustenance, and then burrow through the ground if possible to reach a site that is preferably outside the territory of another, and near somewhere that animals regularly travel. From there it will feed and regularly use a small region here that will become it's primary burrow. The more it eats the quicker it grows.

Ecology and Habitats

Like many species of desert animals, the desert worm is built to survive in the desert. The burrow it builds protects against sunlight during the day and conserve moisture, and if need be tapping underground reservoirs for moisture, using the lower parts of itself to act like a straw drawing this water up. At night, the burrow is warm enough to stop it losing heat.
When the desert worm feeds it strips nutrients from pretty much everything it eats, little is wasted. Small animals about the size of a mouse is generally left alone unless the worm hasn't ate in a long time. This also attracts larger creatures in the process such as predators it can feed on.
What waste is dumped from the body is passed into a specific chamber to one side of its tail end, and can be broken down by microbes. Anything here can be absorbed by the anal end of the worm along with the water. Special fissures are present in this part of the worm to allow it to suck up these and dump it back into it's digestive tract.
For some reason water does not affect the worm and it can survive being drowned. This seems to be a genetic throwback to its origins in the sea, and allows it to hide in oasis water pools.
It rubs off its chitin in the burrow, and mixes it with the sand on either side. This can be beneficial to other animals as well as itself. It allows the worm to grow in size, and there are minor nutrients that other animals can use as a salt lick of a kind. By attracting the animals closer it allows the worm to get prey species if they are close enough.

Dietary Needs and Habits

Purely carnivorous, the desert worms wait for prey to come near them, and usually have a wide territory. They can go for years without eating, absorbing some nutrients out of the sand, with just enough to sustain them until a living prey species comes close enough. They will scavenge any animal carcases in their territory (which can be up to 5 to 6 miles in diameter), and will travel at night to stop from being caught in the sun.
They will burrow down so the majority of their body is under the sand. This protects them from the worst of the sun's rays, while keeping them warm at night, and allows them to ambush better too.

Biological Cycle

The worm grows, and continues to grow. Fortunately it is linked to the desert and most animals of relative intelligence will avoid the worms burrows. They can be sluggish, so are not good at travelling over land, and they are now far to specialised to live in other environments, even at deep sea. 
They grow from eggs deposited in a small pool of watery sand created by its parent, and since they are hermaphrodite, they can breed by themselves if none are close by. They are notorious carnivores and the more they are fed the quicker they grow. Being tied to this and living in the desert means there are fewer than what many would expect. And they never need to move too far either.

Additional Information

Uses, Products & Exploitation

Many worms have a specific use and that is the chitin. Got at a young enough age, the worm will be decapitated and the chitin boiled to remove any harsh biochemicals, and making it somewhat flexible. This can be worked into clothing and especially good armour of medium or heavy varieties similar to steel plate. A side product of this is that it takes spells related to waterbreathing very good, and is surprisingly light compared to steel. Also, the mandibles & spines can be treated in a similar manner and turned into blades. The only problem is getting these in the first place. 
This has given rise to many hunters from local towns & cities hunting the worms to keep them under, and seize the chitin & spines. At the same time, many warlords and national leaders try to lit out their elite warriors with the same substances.

Geographic Origin and Distribution

Only found in the Arabic Peninsula.

Perception and Sensory Capabilities

The desert worm has five antenna on its head that uses a mixture of scent / odour, and vibrations (in part with its spines) to pick up where prey are, and as an ambush predator will wait buried under the sand with it's head just below the surface and the antenna poking out slightly. It has no eyes, and no real working ears, with the closest being felt through the body & antenna instead.

Symbiotic and Parasitic organisms

Small parasitic worms regularly feed in the intestinal contents of the desert worms, and can carry viruses & bacteria into the body that way. Also, if the worm spends too long idle in it's burrow certain fungal infections can build up at the lower ends that can cause damage to the chitin sections on its body.

Lifespan

Unknown

Average Weight

100lbs to a few tons.

Average Length

Anywhere from 1 foot long to 25 feet.

Body Tint, Colouring and Marking

Iridescent colouring with metallic shades of colour.