Sneaking onto the farm, you waste no time finding the object of your desire: a tall midnight black stallion. He was tall and muscular with a beautifully shiny coat that glistened in the afternoon sun. Taking a quick glance to make sure you were well enough away from any judging eyes, you slap the zipper on the Stallions underbelly before he can react and unzip.
In an instant his towering form collapses into a hollow suit. It was surreal, you knew what the zipper could do, but seeing it happen in front of you was a little terrifying yet exciting. Shuffling the suit around you find the opening you made. Peering into the whole was just pure darkness. After you take a nervous gulp you slip yourself into the suit. It was completely pitch black inside with plenty of room to move around, turning around you could see your entrance slowly zip itself close and as the last of the outside light vanished the transformation began.
Almost immediately you felt you body begin to realign itself you could feel your limbs being realigned to fit into the horses. Then a fire spread across your body. Your muscle burned with a bright fury as they began to expand and bulge to fit the equines form. Your bones rearranging themselves to that of a horses. All at once your fingers and toes compressed in on themselves fitting snugly into the stallions hooves. Your neck elongated slowly crawling its way up into the horses head. As your ears traveled up to match the horses, could feel your face begin to elongate itself slowly inflating the suit to match it's shape. It felt bizarre and arousing. Your mouth becoming more and more alien and different, tasting the Stallions own saliva with your tongue. While you were reveling in this sensation you failed to notice that you could see. The field of grass you were standing in before was now visible once again. Even though it was the same field looking at it with a horses eyes made it seem so different. Your entire frame of perception has been altered. Even looking around felt different. The way the muscles in your neck moved and contracted; However your transformation wasnt done yet. Your basking was interrupted by the overwhelming feeling of your ass swelling filling with muscle to match the stallions own. Pressing tightly against the outside of the suit. Before you can fully take in your form one final sensation rocked your body. Your tiny by comparison human cock began to swell as a virile heat shot through it. Thousands of nerves began to form and open up along your expanding meat. You let out your first whinny in pleasure at this feeling. Your cock continues the swell with stallion might, slowly shifting into the flared shape of a well endowed breeder that you are becoming. You begin to stand so you can get a better look at your manhood. Standing up with your powerful build felt weirdly natural, panting you lower your head to view in between your legs and there you are met with the half limp phallus of the costume. Slowly its being inflated by your inner transforming insides slowly creeping towards your face. As this is happening your balls are swelling with virile, potent horse cum, the human cum inside being taken over by the equine seed. Letting out a grown and your now grapefruit sized gonads reach full size, but your cock was not yet. Feeling the your cock fully squeeze up against and integrate with the stallions own was mind blowing. Pleasure and lust shot throughout you body as your equine gonads began to send horse testosterone into your blood. It seeped its way into your brain changing and rewiring it, your once human brain began to change, as new desires and tastes began to form. You didnt loose your intelligence but other things seemed to matter more than they did before like breeding. Things became simpler as other worries seemed to melt away. Letting your mind be consumed by these feral desires sent you over the edge And as you became your new horse self in mind you came, your body tensed up as white hot seed shot from your member into your hanging face. It brought you out of your stupor, lapping it up with your new tongue you smiled. Your body felt powerful, alien yet familiar, and you had one thing on your mind. Breed.