Dimensional Borer

The dimensional borer is a giant Neuropteran (net-winged insect), distant cousin of the antlion. In its juvenile (nymph) form, it has the ability to burrow through the substrate of reality, creating pocket dimensions from which it ambushes its prey.

The Nymph

The borer's hide appears from the outside as a dark, puckered hole in the surface of reality. It looks the same no matter what angle it is observed from, although the more clever specimens will disguise this by building their hides next to a solid surface.

Space is distorted around the hide, making it look as though it were in the centre of a fish-eye lens. All surfaces slope towards it; loose objects roll into it, and anyone who falls in the area will begin tumbling towards the hide. The hide is always closer than it appears to be, and even basic movements become confusing in its vicinity*.

When prey approaches, the borer nymph sticks its head out of the hole and attack by spitting globs of raw reality at its victims. A direct hit can potentially kill or maim the prey by distorting the space around them. However, the real purpose of the spit is to cause localised ripples in reality that knock the victims down and make them tumble closer to the hide. When they are in reach, the nymph will grab them and drag them inside its pocket dimension.

The pocket dimension is small and dark, a maze of pitch-black tunnels in which the nymph fights at a great advantage. Once the prey is dead, the nymph will slowly suck out the 'spatiality' from the corpse and then spit it back into the world. Such corpses are hideously stretched, nearly weightless, and react unpredictably to contact (think of glitchy ragdoll physics in a videogame).

The nymph's mandibles can be crafted into a unique weapon that distorts enemies' perceptions, although the wielder must train for months before they can avoid cutting themselves with it.

The hide itself will slowly decay if the nymph leaves or is killed. However, with the proper rituals it can be stabilised and attached permanently to a portable object such as a doorway or a bag.

The Mating Season

Dimensional borers remain as nymphs for a long time - up to one hundred years - before emerging all at once in response to some seasonal shift in the shape of reality. In their adult form they resemble giant dragonflies. Once they have left the hide they no longer hunt prey, and will die after a few days. Their mating flights cause dire disturbances in the fabric of reality: time skips, spatial distortions and even brief incursions from parallel universes. The borers mate in midair, after which the female severs the male's head and devours his corpse. She then finds a safe place and thrusts her ovipositor into the substrate of reality to lay her eggs.

While many humans fear the coming of the mating season, others see it as an opportunity. Dozens of hides lie abandoned in the weeks following the mating, and treasure hunters comb the hills looking for them. Additionally, the severed head of the male can be crafted into a shield that draws projectiles like a magnet, and the eggs are worth a fortune to wizards studying translocation.

*Readers of Gene Wolfe's Book of the New Sun can imagine the hide behaving similarly to avern flowers.