Source: Alien Archive 2, pg(s). 24
A calecor resembles a big cat made of broken stone surrounded by vines, with wings made of leaves and a head that consists of a holographic globe split into two pieces, perfectly representing the calecor's bonded world in real time. A calecor is 10 feet tall and can weigh more than 6 tons.
During a global catastrophe, as a torrent of souls leave for the Boneyard, some of the life energy from dying fey and non-sentient organisms might tear a hole from the Material Plane to the First World, and combine with the essence of the First World to create a calecor that embodies this calamity.
It is unknown why some catastrophes create calecors while others do not. The best hypothesis is that a planet's resident fey naturally understand its natural order, and calecors are only created from disasters that they deem to be caused by outsiders.
As soon as a calecor is born, it leaves the First World to return to the world that created it. It will then try to undo the damage, stabilise the ecosystem, destroy the structures of the culprits and terraform regions rendered uninhabitable. The calecor instinctively knows everything that happens on or within its bonded planet, although this information is difficult to process.
A calecor's mind is split between the desire to heal and nurture and the painful last memories of the cataclysm's victims, which can be dangerous to those lacking mental fortitude; the calecor can also forcibly project these memories into enemies as a weapon. A calecor lives until its bonded world is sufficiently healed or destroyed beyond recovery; upon the death of a calecor, its head's halves fuse, becoming a calecor skull-globe.
Calecors are solitary creatures and might not even be aware of the existence of other calecors. They are docile towards organisms in need of recovery or repopulation, and make powerful allies to those whose goals align with theirs, but are bellicose towards potential threats to its mision or bonded planet, who will be warned by visions of the calamity that gave birth to the calecor before it attacks.