John continued to run after Carrie as she ran over the hill. Suddenly she stopped. John ran into her, and they tumbled down the other side of the hill. They stopped tumbling as Carrie hit a rock, and John was thrown past the rock and right in front of a large bull, larger than he had ever seen before.
Carrie peered from behind the rock, and watched as John stood up and looked right at the bull. The bull seemed to be looking at him with a lot of anger. Looking down, John realised that he was wearing his red shirt.
The bull snorted, and John started to run. He ran, but the bull ran after him, and started to gain on him. He knew he had to do something, but he couldn't think of what he could do.
Suddenly it came to him. John turned around to face the bull, breathing very hard. His chest expanded and contracted more than it should have. He focused, and breathed in deeply. His chest began to expand, growing larger by the moment. He continued to breathe in, and he was now much bigger than he had been. His muscles started to inflate, growing larger. The bull stopped running as his shirt was shredded by his inflating body. His pants followed, revealing yellow boxers with blue hearts.
John blushed for a moment, his face turning bright red, redder than his shirt had been, but he continued to breathe in. His body continued to swell, his muscles now rivaling the biggest bodybuilders on his own planet, and continued.
John heard a creaking sound, and then suddenly his boxers exploded from his body. He stood there, fully naked, his huge inflated form growing.
He was now as large as the bull, and suddenly John felt extremely itchy. He stopped his inhalation and scratched his chest. Looking down, he saw hair growing from his huge pecs. The hair grew and thickened, and he could see hair also growing from his arms and legs.
John breathed in again, and all of the air went to his already swollen phallus, which then continued to grow. John felt strange, and suddenly fell forward, catching himself with his fists. John tried to stand up again, only to find that he couldn't.
John felt pain as two large horns grew from his head, and then more pain as his face pushed forward into a muzzle. He snorted as he grew a tail, and then his entire body seemed to writhe.
His body shifted, the proportions changing, and suddenly what stood there was no longer human at all. John was a bull, and was larger than the one that had been chasing him.
With a loud snort, John chased after the smaller bull, his horns down and ready to inflict damage. The smaller bull seemed to pause for a moment, and then it ran out of the field like a bullet, leaving a trail of fire.
Turning, John saw Carrie hiding behind the rock. He trotted up to her, and stood, waiting.