Looking through the old White Dwarf Presents and the Warhammer Quest Roleplay book we have these mentions of BCs:
At the pinnacle of the city is the Temple of Hashut, the bull-shaped god of the Chaos Dwarfs, who they call the Father of Darkness. His temple is guarded by Bull Centaurs, creatures mutated from Chaos Dwarfs long ago. They have the body of a bull but the torso of a Chaos Dwarf, with long snaggly tusks and exotically curled beards.
(White Dwarf Presents: Chaos Dwarfs, p5)
Bull Centaurs are creatures with the upper torso of a Chaos Dwarf but the body of a ferocious bull. May centuries ago, when Chaos Dwarfs were first twisted by the powers of Chaos, some of their race were transformed into Bull Centaurs.
These powerful creatures guard the great status of Hashut in the Temple atop of the Tower of Zharr-Naggrund.
(White Dwarf Presents: Chaos Dwarfs, p40)
Bull Centaurs are creatures with the upper torso of a Chaos Dwarf but the body of a ferocious bull. Many centuries ago, when the Chaos Dwarfs were first twisted by Chaos, some of their race were transformed into Bull Centaurs. Since those days the Bull Centaurs have guarded the great statue of Hashut in the temple high atop the Tower of Zharr-Naggrund. They are as keen witted and intelligent as Chaos Dwarfs and completely devoted to the worship of Hashut the Father of Darkness.
The Chaos Dwarf Sorcerers trust them completely, and often entrust them with complex or dangerous tasks. Although they are few in number they are more powerful than Chaos Dwarfs and much swifter in battle. Even through there are mighty individuals amongst them, there are no sorcerers in their number.
(White Dwarf Presents: Chaos Dwarfs, p50)
Bull Centaurs are arrogant and cruel creatures, utterly dedicated to the Masters of Zharr-Naggrund and their horrifying deity Hashut the Father of Darkness. Bull Centaurs wear light armour and carry shields. They are armed with brutal double-handed axes
with heavy cleaving blades.
(White Dwarf Presents: Chaos Dwarfs, p60)
Bull Centaurs are Creatures of Chaos : beings with the upper torso of a Chaos Dwarf and the body of a ferocious bull. They are keen-witted creatures and powerful fighters.
(Warhammer Quest Roleplay Book, p99)
Warped and malign creatures, Chaos Dwarf Bull Centaurs are, as their name suggests, twisted amalgams of Chaos Dwarf and ferocious bull in aspect, the unnatural fusion creating hulking, monstrous beasts far larger than either and filled with cannibalistic appetites. Many centuries ago, during the Time of Chaos, a fraction of those that survived the onslaught became horrifically mutated, their stubborn Dwarf resistance to the warping taint was overwhelmed utterly by the awful energies to which they were subjected, and so the first Bull Centaurs were born. They came to serve their wider kin as shock troops and temple guardians, and to them was entrusted the protection of the sacred fanes of Hashut, as they more than any other had been twisted to the closest semblance of the father of darkness’s image. Into each successive generation of Chaos Dwarfs a handful of new blessed kin has been born - usually to the death of their unfortunate dams, and such children are given over immediately to the Sorcerers to serve in turn. This number however has not proven enough, and Hahsut’s inventive priesthood have wielded their dark arts to make more, tampering with their offspring using horrific magics, and even fusing them into frameworks of metal and demon tainted flesh to swell the ranks of their temple guardians.
(Tamurkhan, p174)
So in the Tamurkhan book the BCs in the Legion of Azgorh are born already mutated, but then the priests also create their own… which I don’t think any of us have ever followed up on to any great extent on here! It certainly presents some unique opportunities for steam punk style variants and conversions!
~N