Zaratan

Asleep on warm southern currents, a zaratan looks like a small drifting island. Its sloping, rocky shell spans several hundred feet (AC -6). The 50-foot head passes for a barnacled boulder, its eyes hidden under stony lids, and each of the four flippers, over a hundred feet long, resembles a strip of reef crowded with coral and small fish. Its head and flippers are softer, at AC 0.

Woken, a zaratan usually just withdraws into its shell, where nonmagical weapons cannot harm it, and stays there 1 to 10 years unless provoked further. Its metabolism is so slow that no known poison affects it.

Once wounds exceed 5% of its total hit points, the turtle fights back. It always acts last, but its 40-foot jaws bite for 10-100 damage, and if the attack roll succeeds by 4 or more it also swallows every being within 10 feet of the target, no save.

The stomach is a tough tubular cave (lining AC 5) holding enough stale air to breathe indefinitely, though digestive acid deals 2 points a day to the unprotected. Wounding it from inside for a twentieth (5%) of its hit points gives it indigestion, and it spits everyone out. Its belly might hold driftwood, wreckage, arms and armor, and a little treasure (type Z suggested). After any fight it drops back into sleep for 1-100 years.

Zaratani (the plural) live for millennia, and legend claims they drifted here before the genies ever came to the desert lands. Any one is 99% likely to be asleep, jaws open; anything up to man-sized that swims in, mostly big fish, is swallowed by reflex. Waking hours go to mating and talk. Every few centuries two bump together by chance, and if they wake and are of opposite sexes a courtship of decades and a mating of up to a year follow. Their whale-like speech makes single conversations last decades, and now and then one speaks telepathically to other beings.

The older a zaratan grows, the longer it sleeps, until it is indistinguishable from an islet, palms and all. Elders tolerate tenants who stay quiet. Some carry primitive villages, and pirates have used others as roving bases. Island dwellers often worship their home as a god, rightly fearing that a hungry awakening would drown them, so they keep it fed with heaps of fish and the occasional visitor.