Nyth

A nyth is a sphere of radiance that can change its color and brightness at will, which is why people so often confuse it with its better-known relative, the will o' wisp. It speaks common and the flashing light-language of wisps, can talk telepathically with most creatures, and picks up any language it hears often.

Floating silently by natural levitation, a nyth hunts birds, rodents, big insects and other small prey. On bright days it likes to drift with the sun at its back, hidden in the glare until it strikes. It bites what it can hit, but its main weapon is an innate magic missile, the same as the 1st-level spell, fired every other round for 1d4+1.

Against dangerous foes it dodges, uses its wits to spot spellcasters and magic items and disrupt them, and tries to talk enemies into pits, bogs or traps. Like a wisp it can douse its glow for 2d4 rounds to sneak up or slip away, visible then only to those who see invisible things; firing a missile makes it flare and stay visible that round.

Any weapon can hit it, but fire, lightning and other raw energy feed it, adding their damage permanently to its hit points until lost to other attacks, so fireball and lightning bolt cannot hurt it. Magic missiles aimed at it are reflected back at their source. It does not heal by resting, instead seeking campfires and forest fires to refuel. Its strange, layered, chaotic mind is immune to all enchantment/charm effects, in addition to its magic resistance.

Nyth wander alone, without territory or lair, though they have favorite hunting grounds and haunt lonely ruins and wastes where their light will not draw enemies. They have never been seen fighting wisps or each other. Once a nyth has absorbed 60 or more hit points, it splits in a spectacular burst of light and wild magic missiles, each living creature within 30 feet taking 1 to 3, leaving two 7 HD nyth. Some barbarians call them 'wildfire' and think them evil spirits; most folk avoid them and are avoided in return.

Their talents make them superb guardians, and guardians are the only nyth most people ever meet. A lonely nyth is delighted to be accepted and given a home, whether a room, cave, crypt or crossroads. With clear orders and regular meals of fire and energy, not just live prey, it guards that place proudly, using guile and wit against intruders and retreating only when it faces certain destruction.

Wild nyth prey mostly on birds and other small woodland and coastal creatures and leave little mark on their surroundings. No magical use for their essence has yet been found, but wizards expect it to prove handy for new items and spells tied to fire or magic missiles.