Urban Fantasy: Astral Life forms

We generally assume that 'life' is of the material: cells formed of proteins forming a larger organism. Yet life exist beyond the material, composed of the paradoxical 'immaterial matter': stray thoughts, concepts and ideas. As always, these discussions return to the concept of Spirits yet they are not the only form of immaterial life. There exist a parallel 'order' of immaterial beings which are Spirits but not quite Spirits with a capital S. Thoughts, ideas and mental energy form their ephemeral bodies but they are not driven by their embodiment of concepts. These creatures are of a lower, more primal order. They are crude, often almost mindless creatures. They are often animal, predators or parasites.

Astral Entities

Art by Jurasbatas.

Astral Entities are a form of Spirit in so much that they are made of spiritual matter and can be repelled or controlled by the same means a more defined, or 'proper' Spirit can. The difference is that Astral Entities are the 'animals' of the Spirit World. This term can be a bit confusing, as there exist spirits of animals which embody animalistic  traits but Astral Entities exist aside from them. Their 'spiritual bodies' and composition is crude, with little more than a limited intellect, sensory abilities and some mean to attack and kill living beings (or, in some cases, parasite them). They are of a lower order of complexity, much in the way we'd consider bacteria or virus to be 'less' than a human given how complex we are. Yet these things can and do kill us and the same is true for an Astral Entity. Phantovores are an example of creatures which straddle this line.

By themselves these creatures drift across countless astral spaces, immaterial and mostly unthinking, feeding off stray mental energies mostly harmlessly. In our daily lives we encounter an uncountable number of these entities as they brush off our reality for a split second, to the even spiritually aware people don't even notice them. The danger emerges when one enters another dimension, another world or plane of existence where the spiritual and material are one and the same. By themselves most Astral Entities are too weak and stupid to ever enter our world but when someone impede upon their domain and hunting ground they will pounce. Since Astral Entities have no true form, they will shape themselves to become part whatever psychic environment one is visiting, assuming fake forms which are thematically appropriate.

Astral Entities, by themselves, are at best an environmental hazard or a one off random encounter to explain to players that sticking too long in some spiritually active areas might be a bad idea, as it might attract hungry metaphysical predators. They aren't particularly interesting monsters by themselves. However, these creatures can be used as part of a greater adventure:

• Any antagonist to the PC with access to spirit-related abilities or spells could use such a knowledge to harass the PC, summoning predators to hunt them down and keep them away from astral planes. These creatures would take the form of hunting beasts and attack them whenever they are either isolated or close to a spiritually potent area. Thus, they can be used as 'mooks' by an antagonist. Weak but eternally replenishing minions.
• Most Astral Entities are fairly weak but a singular, high HD one could have become stable enough and established a lair in an area of some other plane, where it thereafter functions much in the same way as any monster with a lair, making the area difficult to approach. Given their form reflect the themes of an area, this can potentially be used to change the pace and use some monster from another genre or game.
• Astral Parasites can be the focus of an adventure. They are similar in function but they don't eat those they attack, instead implanting a spiritual 'egg', much like how some wasps (or the Xenomorph) do. Once it is done sucking on the mental energies of the host it pops out, temporarily with Manifestation at Rank A and attack, implanting its own eggs in the process. Left unchecked this can create an epidemic.
• Astral Entities can also be used by players as temporary minions or even messengers, should they need to acquire and send information but suspect their phones or other methods to be spyed upon.