Shard Dragon

Deep beneath the mountains of the Old World dwell the creatures known to myth as Shard Dragons. Enormous serpentine beasts, Shard Dragons prowl the black depths of the world, stalking their prey in the abject darkness, pulling themselves silently over rock and shale on disturbingly prehensile, sickle-clawed arms. Their pale flesh is covered by long jagged scales, each razor-edged and wickedly pointed. Coated in blood and decaying viscera, these protective plates are as much a weapon as a defence, slicing flesh and puncturing the armour of those foolish enough to confront such creatures in battle.

These subterranean terrors are renowned amongst the Dwarfs for their stubborn, unyielding ferocity, and against their bestial kind are many entries in the great Book of Grudges lodged. Shard Dragons will attack almost anything they encounter, from the bulking white-bloated fungoid slugs that swim the lightless seas of the under-earth, to the heavily armed Dwarf mining crews that brave the deeps in search of gromril, and lay waste to all. If any Shard Dragons manage to break into the subterranean domains found closer to the surface -- be they of Dwarfs, Skaven or Goblin construction -- they will reave bloody murder and glut themselves on flesh until slain or they slink back into the depths, their bellies full.

Creatures as much living nightmare as bestial predator, there are those loremasters that claim that Shard Dragons are not 'true dragons' as such but the devolved remains of some draconic offshoot that migrated into the dark heart of the world. Untold centuries in the lightless umbra have filled them with malign power and distorted their forms, and some are now venomous enough that they burn the very rock beneath them, while others are able to exhale the vaporous essence of soul-destroying terror to silently slay their prey, and should they be overmatched and injured the Shard Dragon will explode into a murderous rage that few creatures can survive.

It was the Dwarfs that first returned these creatures to the light of the sun, having learned to bind Shard Dragons with powerful runic collars and turning them upon their foes to rend and tear. Learning of their power ambitious wizards, now long dead, soon created binding scrolls so that they too could harness the Shard Dragons' strength.

Source

 * Monstrous Arcanum pg. 72