Creature Concept: Sinkhole Vine

Scholars are unsure of of the beast's exact origin, but research into them (with more then a little concurring knowledge passed on from Druid orders), have come to the near universal conclusion that despite looking like a plant the creature is in fact an affront to nature in all it's forms, ones even druids willingly purge when found.

The Sinkhole Vine is dangerous not for is ferocity but for it's subtly. The vines grow from seedlings over the course of decades and sometimes centuries, year by years eroding and consuming earth and stones to fuel their growth, reaching further and further towards the surface, all the while creating massive sinkholes beneath them, for which their name comes from.

Most unsettling of all is these vines, despite not being innately carnivorous are almost always found to take root under stabilized settlements of humanoids. It's theorized by some that the creature harbors some innate hatred towards humanoid and the settlements they build, but are also no guardians of nature as other misunderstood creatures like Treants are.

This is because the stone and earth they devour is utterly destroyed, consumed to allow the beast to grow to truly colossal size. In short, unlike every other known plant the Sinkhole takes from nature without ever giving anything back.

Yet still it seeks to reproduce as other plants and animals do, but only once it has succeed in it's task of collapsing villages, towns and in the case of larger varieties whole towns or forts. Once it succeeds and nothing remains put a massive gaping chasm open to the sky and elements the beast undergoes a starting metamorphosis. it's usually sickly green tendrils covered in green and inner purplish leaves slowly wither away turning into lifeless gnarled roots.

Drawing all of it's life force towards the massive tangled core that is it's true "mind" it forms a single giant polyp like growth, slowly building in size and pressure until after a week or more the mass finally explodes with immense force, killing itself and sending hundreds of thousands of small, windborne seedlings into the air, counting on the force of the blast the prevailing winds to spread it's children far and wide.

The overwhelming majority of these seeds end up either consumed by various wildlife like birds and small animals like mice and squirrels, and those that do land in inhospitable non-temperate terrain like mountains and deserts have no chance to take root, even those that land in open places like fields and forests wither and die, despite plenty all other forms of plants being able to flourish or at least make due in such places, once again pointing to it's unnatural origin.
Only the scant few seeds that find their way towards caves and ravines take root, even then they grow slowly and do little damage, those that find their way beneath villagers and cities, such as being sucked into a sewer grate or into a sturdy cave network a fortress was built over.

Dealing with mature, growing Sinkhole Vines is a matter of timing. If found to late then destroying the malevolent creature may very well cause a partial or entire collapse of the terrain above it, as it's inching tendrils are the only thing keeping the terrain semi stable, even if full intends to collapse it all into the void beneath.

If discovered to early when it's crevice home is too removed from the surface it may be to difficult to remove, miners having to spends years trying to dig to it's location, all the while the creature growing larger and causing even more irreversible damage.

The "sweet spot" for finding a Sinkhole Vine is when the beast has dug a big enough hole to be noticed by discovery or chance, but the ground above is still stable and sure enough that once removed it can be left be or buttressed by man made supports to keep it from total collapse, these works cannot be done while the creature still lives, as it will actively seek out and destroy works of wood and metal, and consume those of stone and earth like it does so normally.

The creatures are known by druids and natural loreists to be at least semi sentient, but those few who have tried to commune with it's conscious report a detached, unknowable conscious, like the profaned mind of eldritch horror. The very act of trying to commune with it sends the beast into a panicked frenzy, as if the projection of consciousness pains it to no end, something it simply cannot understand despite Druids and other like vocations having the talent to communicate with normal flora without problem.

Combating and destroying a Sinkhole Vine can be just as arduous of an endeavor as reaching it in the first place. The giant core mass itself has no maw or other orifice to speak of, but is often tough and covered in matted tangled vines that prove proof against blunt weapons and the slashing of swords and other light edged weapons. Only the haft of a swung axe or greatsword, or the powerful thrust of spear or dagger seem to have any noticeable effect, even then only a moderate one.

What truly affects a Sinkhole Vine is fire. The beast loathes and actively stays away from any source of flame or heat, and it reels in pain if set alight by fire, mundane, magical or otherwise, it also has no love for cold, becoming brittle and is easily hewn apart by might once frozen. It holds no special resistance to acid or electricity but no weakness either.

If attacked a Sinkhole vine will relate by uprooting some of it's vines and whipping them at it's attackers, using it's innate tremor sense to find and attempt to grapple and squeeze them to death or simple dropping large vines of them like large cudgels to crush them utterly.

This is dangerous for more then the obvious reasons that come from fighting a giant creature, namely that as vines are hack or burned off and rendered useless the monster will pull more and more of it's tendrils off to fight back, weakening the earthen walls all around it and it's aggressors. Every newly replaced vine risks total collapse of the space it occupies, and such a collapse with likely be utterly fatal for the dauntless heroes, and even if they do escape there is no guarantee the collapse will be enough to kill the Sinkhole Vine, it may simply be delayed for a few years or a decade almost, to make sure it's dead it would have to be dug out and set alight, a grim prospect given that it's ultimate goal of destabilizing the world above may be partially or fully completed.

If successfully killed Sinkhole Vines are known to quake and tremble in it's death throes before collapsing motionless, all it's vines falling so as well as over the course of few minutes it's body turns gnarled and lifeless, decaying into nothing after no more then a few hours, but not creating or spreading any seeds either, as it failed to reach that cycle in it's life.

Battles such as this inevitably breed speculation on who or what brought such a horrible mockery of nature into being in the first place. Druids have encountered such profane things for centuries, having heard, read and told about encounters with things matching the description of Sinkhole Vines dating back thousands of years.