Moon Dragon

A moon dragon's hide runs through a 30-day cycle. It starts pure white; a dark shadow appears on the left flank and creeps across the body over 15 days until the dragon is black, then a white sliver emerges on the left and spreads over the next 15 days until it is white again.

Each phase lasts seven days and changes the beast. When all black it fights at full strength and is chaotic evil. During the half-black and half-white phases it is neutral evil, with powers and combat modifiers at half its age category. Fully white, it turns lawful evil and operates at a quarter of its age category, so an old dragon fights as a very young one. Size and Intelligence never change. While it is all white, any lycanthrope nearby instantly takes animal form and, unless it saves vs. magic, obeys the dragon as if charmed.

Melee bores it; it disdains its 1d4 claws and bite. Provoked, it breathes first, hoping to start a rout, breathes again if the foe stands firm, and tosses in a spell now and then for variety. The breath is a cone of black frost 160 feet long, 10 feet wide at the mouth and 40 feet wide at the base, dealing 2d10 damage. Anyone failing a save vs. breath weapon is frozen into a block of black ice holding 1d4+1 rounds of air, then suffocates. A trapped victim may try a Strength check at -2 each round to burst free; rescuers need 1d6 uninterrupted rounds of chipping, or magical fire, which frees the victim after 1d4-1 rounds but deals any surplus damage to the victim.

Cold cannot harm a moon dragon. It sees exceptionally well, and are unaffected by light and darkness spells. Each of these gains is usable 3/day: light (young), darkness 25-foot radius (juvenile), continual light (adult), minute meteors (old), repulsion (very old), reverse gravity (venerable).

Found only in caves on moons, they crave wealth and power like other dragons and are snobbish and conceited, fixated on lunar themes and the contrast of light and dark. Hoards favor black or white pearls, diamonds, moonstones and any coin its makers call a 'moon'. They speak the common tongue of evil dragons, and 20% of hatchlings can converse with any living creature, plus 5% per age category.

Broods hold 1d4 eggs. Moon dragons eat nearly anything and stock a larder of frozen victims, so they seldom need to hunt across their moon. Sun dragons are their sworn enemies, attacked the moment they are seen.