The tarasque of legend may have been a relatively standard dragon, but the tarrasque of role-playing has become something else entirely: a mythic beast of utter destruction. I don’t need to go through the litany of its attacks, defenses, regeneration, etc.—because they don’t matter; it simply cannot be killed. The best you can hope for is to divert it, banish it to another realm of existence, put it to sleep, or prey for divine intervention…and even these methods will likely burn every wish and miracle the PCs can scrounge up. It is, quite simply, a living apocalypse engine. Its appearance alone is a history-making event, and any adventure that involves the tarrasque should take that into account.
Speaking of which, props to Pathfinder’s Golarion setting for working the tarrasque into the world’s very origin story. The tarrasque is such an exceptional creature that it tends not to fit into most worlds because it raises so many questions: What spawned it, where has it been hiding all this time, why do the gods not get involved to stop it, etc.? Golarion answers all those questions—the evil god Rovagug; the Pit of Gormuz; they have, but even they can only do so much—and gives the tarrasque equally terrible cousins besides (see the Inner Sea Bestiary or Mythic Realms). All in all, a sign of really comprehensive worldbuilding.
A tarrasque comes out of the Emerald East, driving hitherto undiscovered creatures—girtablilus, vemeraks, kongamatos, and even the elusive cobra and hippopotamus lords before it. Impaled upon one of its great horns is the broken body of the still-living asurendra foolish enough to have summoned it from the bowels of the earth.
The crew of a crashed voidship carries dire news: An asteroid has been pulled from the Shatter Belt and is hurtling earthward. Investigation reveals a cabal of human cultists, moon-beasts, marsh giants, and rune giants have conducted dread rites to reknit the world’s ley lines into a glyph of summoning…and the Old Ones Beyond the Stars have answered. An angelic cabal manages to deflect the asteroid enough so that it lands in the ocean, preventing an extinction event, but the asteroid hatches and a tarrasque emerges.
A dullahan of exceptional power rides into the capital with a message: The nation has been judged—and found wanting. The tarrasque is coming. The headless horseman is not the only herald—kytons begin evangelizing in the streets, offering freedom from fear through transformative pain, and an akhana and kolyarut take up residence on the cathedral dome as enigmatic witnesses. But as the tarrasque nears, divination reveals it was supposedly sent by the gods of law and good. If this is true, what foul act has inspired this Judgment Day?
—Pathfinder Bestiary 262
I just got my email that says my copy of the Bestiary 4 is on its way. I imagine the tarrasque will soon have some company in terms of sheer power…