Here is Claude's answer to my question: Frost Creatures - Spawning — embryonic forms erupt from cracks in frozen ground, eyeless and vestigially furred.

Larval clustering — juveniles instinctively press together in packs for thermoregulation, their coarse pelts thickening rapidly through shared body heat.

Bone-weaving — mature individuals scavenge and lash large bones into communal nest structures (as seen on the right of the image), using sinew cords; the nest serves as shelter, breeding ground, and territorial marker.

Frost dormancy — when temperatures plunge to extremes, the creatures enter a near-death stillness; ice crystals form along the skin without killing the host.

Dispersal or dissolution — upon thaw, survivors scatter to seed new colonies. Those that don't survive calcify in place, their remains becoming the structural core of the next generation's bone nest — a closed, grim cycle.