I knew Sara wanted to win the race very badly, but I did not want to make it too easy for her. On the other had, with her huge cock and a desire to run fast it was pretty obvious what I should maker her into. I grinned as a thought occurred to me.
"Sara, I wish that you and all of your competitors and teammates would become anthropomorphic, hermaphrodite horses and that noone would remember that you were any different except for you and me."
"Joey!" protested Sara as she began to change. "I said make it so I can win!" With each word, her voice deepened. Sara grew taller and more muscular as a deep brown pelt covered her from head to...hoof! Sara's running shoes were gone, unnecessary now that she had shiny black hooves. Her hair became a midnight black mane, and a matching tail unfurled behind her, her shorts adapting to allow for the tail because of my earlier wish that her clothes would always stay on.
I looked up at her, impressed at her size and strength. Her face had pushed out into a slight muzzle, which I thought was very cute. Her eyes were a mix of horse and human, large and round but still a light green. A white blaze ran down the length of her new muzzle to her soft nose. "You are really sexy this way!" I told her.
Sara snorted in a very equine way and held out the waistband of her shorts. "At least this sheath will make it easier to run," she said in her new, deeper voice. She reached a little deeper and gasped. "Oh my! I've got both!"
"Well I did say 'hermaphrodite'", I reminded her.
"Never mind that," she said as she readjusted her shorts. "You were supposed to make it so that I can win. But you changed everyone!" She waved her hand at the other track girls, who were all sporting new hooves and tails. In the middle of the field, some Clydesdale and Shire girls were hefting shotputs. Quarter horses were sprinting on the track, while other breeds were warming up elsewhere. I even saw a few zebras that I thought had been the relay team, though it was hard to tell how many there were...they kind of blended together.
"If we're all horses, I don't have an advantage!" moaned Sara.
I smiled at her and patted her bottom as though she were a normal horse. "You're a fine Arabian mare...umm..stud...well, horse. You'll do great!" I told her. "Besides there is no more time for arguing, the race is about to begin."