Lythlyx

Often called spirals, lythlyx are long, wormlike beings as thick as a person's thigh, with oily, rubbery, flexible hide mottled black and green. They haunt remote places, whirling like corkscrews in the air or underwater, and may dance in one spot for a year at a stretch. They have no real head or eyes but see with 90-foot infravision through sensitive patches all over the body, and seem untroubled by extreme pressure.

Lythlyx are hostile but fickle, sometimes skipping easy prey to go after stronger or larger groups. Each round they choose one attack mode, though size and position may let them use it on several foes: lashing like a whip (2d6), snapping coils around prey and squeezing (3d6 per round), or draining blood through any of their 20 sucker mouths (1d4 per round per mouth). Once it has drunk blood equal to twice its maximum hit points it is sated and lets go. Within two rounds the blood becomes energy, healing 1 hit point per 4 points of blood taken, and a healed lythlyx promptly feeds back up to satiation. Violent death often makes it burst in a spray of blood.

It flees stronger enemies when it can and fights to the death when trapped. It uses psionics only after losing more than half its hit points or when someone within 90 feet manifests psionics, and its powers can whisk it out of most danger. Its psionic sciences are create object, teleport, summon planar creature and psionic crush. Its devotions are molecular agitation, control flames, animate object, create sound, control sound, suspend animation, body equilibrium, teleport trigger, mind thrust, telepathic projection, id insinuation and psionic blast. Sleep, hold monster, fear, command and charm have no effect on them.

They never land by choice and thrash wildly if forced down. In flight they whirl at least 50 times per round, can hover while spinning, and can dive at double speed (MV 24), steering precisely by spin. If the spin is halted, the lythlyx drops helplessly, but air drag turns and slows it, so impact deals only 1 point per 10 feet fallen.

They are mute and apparently hermaphroditic, bearing live young that swarm with the parents and gorge until fully grown, then usually drift away. They seem to live for centuries. Sages variously guess they are a life stage of tentacled horrors like tentamorts, ropers or gibbering mouthers, kin to couatl, or part of some dragons' life cycle.

Its hide drinks in light and water and can go long stretches without blood. Oil rendered from its flesh goes into certain magical inks and oils. Most predators find its taste and smell so foul that they eat one only as a last resort.