Ghost spiders

“They say each eye of a ghost spider sees into a different Realm.”

— unknown

Ghost Spiders are a species of Monsters present on most mortal realms. They are highly dangerous but also occasionally used as sources of wealth or as beasts of war.

Ghost spiders build their nests in forests and caves and avoid areas that are too hot or cold.

Life cycle:

Ghost spiders are born from light gray eggs about the size of a human torso. They are immediately able to produce webbing and grow up over the course of roughly 10 years to their mature size.
Male spiders stop growing beyond the size of an horse while females never truly stop growing, though it does slow down signifficantly after reaching maturity.
Female spiders lay eggs once per year. As a female grows both older and larger, it is capable of producing more eggs each year.
Ghost spiders can live up to 200 years old.

Dimensional Tunnelers

Ghost spiders seem like normal, if oversized, spiders. They are remarkably frightening, tough and with a highly potent paralytic venom, that much cannot be denied, but by themselves they do not seem very exceptional.

However that is only when seperated from their webs. For the ghost spiders have a special ability to produce webs that naturally tear gaps into the realm shell of material realms and spread to other realms. If a cluster of webs suddenly seem to fade into existence near you, a ghost spider is weaving its web on the other side.
The webs of the ghost spider form weaken the realm shell of a world in a controlled manner. A sufficiently large cluster of webs may create stable portals leading to other worlds. These are not very safe to traverse, but that is only due to the presence of the ghost spider. If the spider is distracted, sated or dead, the portal is safe to traverse. The portal remains stable until such time that the webbing degrades, which happens if the spider is not there to renew it.
Fresh Webbing of a ghost spider is a potent alchemical and arcane ingredient and thus its harvest is a dangerous but worthwhile task.

World walking
Ghost spiders have the ability to wander between the worlds that their webs connect to and can see what is near their webs in other realms, being able to see multiple realms at the same time. This allows them to ambush prey by suddenly shifting across worlds near a cluster of innocuous seeming webs, appearing like a ghost. Thus their name.

Young ghost spiders are primarily ambush predators, preferring to cover an area in webs that grant the spider high mobility, appearing near their prey and paralyzing it with their bite.
Older ghost spiders prefer to use their sticky webs to trap unweary prey or use their size to intimidate prey to cause it to flee into a cluster of webs to get stuck.
If sated, ghost spiders tend to wrap prey in their webs and carry them to their nest to store them for later consumption. This may lead the prey to potentially be stored on an entirely different realm than its origin realm.

If faced with actual danger, a ghost spider will always attempt to flee, mostly to another realm. The only real exception being when it is currently defending a clutch of eggs, at which point a ghost spider will fight to the death.
A ghost spider cannot world-walk if it is seperated from its webs.
A preferred tactic of ghost spider hunting parties is to lure them away from their webs and then kill them with teams of spearmen.

Intelligence

Ghost spiders are remarkably intelligent. They are capable of pattern recognition and are thus able to recorgnize and distinguish easy prey from more dangerous foes.
They are capable of advanced planning, such as being able to sneak near a prey's burrow and using their web to weaken the local realm, then jumping straight into the burrow to catch its prey unaware.

Communal Species:
Ghost spiders can also live in communities. If there is sufficient food available, ghost spiders will see no need to spread their populations out. They will even cooperate on hunts for larger prey and defend their collective nesting grounds against intruders.
However these creatures have no inherent loyalty or empathy and will cannibalize eachother if they are hungry. Older spiders will not shy away from devouring the younger ones if food gets sparse.
They also do not have any advanced form of communication and thus will not pass down tricks and strategies down across generational lines. This means that older ghost spiders are always more dangerous than younger ones.

Ghost spider colonies can appear rather small, but due to their unique abilities the colony can be spread across multiple worlds. A colony can thus be larger than it appears.
Colonies with more than a dozen spiders are exceptionally rare and most ghost spiders are solitary creatures.

Tamed Spiders
Due to their high intelligence, ghost spiders can be tamed as beasts of hunting or war. They always remain dangerous, but can be trained to respond to commands when rewarded with food. However its spinnerettes will have to be burned out to prevent the spider from escaping, preventing it from using its world-walking abilities.

Variants

Rock Spiders
A close relative of the ghost spider is the rock Spider. These arachnids lack the ability to produce webs all-together and are unable to see into or travel between different worlds as ghost spiders do.
However their carapace is even more durable than that of the ghost spider, they are more aggressive, are capable of burrowing through solid rock and can camouflage themselves to look like mundane boulders if they bundle up their legs and don't move. They commonly build underground tunnel networks for their colonies to inhabit.
They are dangerous ambush predators and very difficult to take down for even experienced monster hunters.
Rock spider colonies compete with ghost spider colonies and thus do not get along well with them. If two colonies meet, one will usually be forced to migrate by the other.

Appearance:

Ghost spiders are human-sized upon hatching, Horse sized upon maturity and can grow up to be the size of small houses if they live long enough. However these old spiders are very rare.

They are commonly a gray coloration, though black and white are not unusual.