Bride of Brock

Among the Kallowa there is a legend, some one call it an old wives tale, of the Bride of Brock. The story generally is told like this.
"On a night much like tonight, the planets were red in the evening star. A dark and dangerous omen. The stars were said to blaze hot and red, pulsing to a drumbeat unheard by any beings ear. The dark sky was lit up for a moment by a comet that streaked blue and yellow across the sky before landing somewhere in the desert beyond. As the fates would have it a young girl, lost and on the run from her tribe, saw the crater left by the comet and approached.
Inside she found a large rock, nearly completely preserved, but an ooze, dark and wet slipped off the rock and for a moment took a shape one that resembled her. It searched her past and her thoughts looking for the reason why such a young girl would be out in the desert alone. Then it found it. She had been betrayed by her family, by her friends, by her tribe and cast out. The creature understood these things and showed them to her.
'would you like to fix this?' it asked. 'I want to destroy them,' was her reply.
And that was exactly what the creature wanted. In that moment it leapt on her, but did not devour her but instead it melded with her the two creatures becoming one. The Bride of Brock as the creature was soon called was now alive.
Vengeance became their mission. The two returned, joined as one, to the tribe that had shunned her. They saw her and drew weapons to run her off again, but her ally caused her to be covered in a thick black mucous and she grew to nearly triple her size, towering over the greatest men of her tribe. She moved quick grabbing a man, her father's brother, and while he reached back with a spear she slammed his head into her mouth and with her now razor sharp maw decapitated him instantly. The rest were dealt with similarly. Claws slashed open bowels and arms were pulled from their bodies with great strength. The Bride of Brock did not finish until her entire tribe had been eliminated.
And so, with the taste of vengeance in her mouth she turned inward and asked Brock, 'What next.'
'Now, my bride. We pursue my vengeance. My brother is here and he must pay for what he's done.'
It is said that the bride wonders these very deserts, looking to avenge any slight or anything that angers the pair. All while they search for Brock's long lost brother.
So be careful on these dunes and be careful which creatures you take help from. You may be forever indebted."