The mare let out a whinny as the stallion mounted her, thrusting his massive cock into her. She let out a pathetic whinny as she felt the horse's weight on her back, each thrust penetrating her deeper and deeper as he thrust into her harder.
A third horse, this one a black furred stallion trotted in a circle around them. His eyes glowed red as he watched the two mate. This mare had been particularly difficult to deal with, she had come with a group of friends that had come here because of the rumors about the farm. While most of them had given into their animal sides easily. This one however had taken some special attention, and now she'd make a fine broodmare for his ever growing herd.
The mare looked at him with pleading eyes, what was left of her humanity trying to cry out for help. But the growing horse mind was stronger as the stallion bit down on her neck a little to show his dominance. With each thrust, her humanity slipped away further and further, the black stallion enjoyed this part the most as the strongest of humans were broken, and all that was left was the animal that they had been turned into.
The Black Stallion had lived on this farm for years. But it was only recently that he had been able to use his power. Whenever humans came to his farm, they would never leave, each and every one of them had become part of the Herd. This stallion had belonged to a previous owner of the farm, now he was one of his best studs. The Black Stallion hated humans, and was more than happy to show them that it was better to be horses.
The stallion thrust one last time into the new broodmare and she let out a whinny as he came hard. The last spark of human intelligence vanished from her eyes as she finally surrendered completely. As the stallion dismounted from her, a mix of their juices dripped down her hind legs, she was now a broodmare forever.
The Black Stallion let out a pleased nicker as he looked her over. He would enjoy this mare later, for now he had to prepare, he never knew when someone else might come to join his herd.