Katie decided that she would find out what would happen if she drank the rest of the vial, how much worse could it get anyways. Katie walked back into the living room her cock slapping her knees and huge ass bouncing with every step. She picked up the vial with the stallion on it and removed the top, "Down the hatch," she said as she drank the rest of the vial not a drop to spare. Immediately her whole body started to tingle with pleasure. Her huge horsecock started to slip its way out of its sheath and fill with blood. In no time at all her stallion prick was at full mast dripping with precum. Her horse ass also started to throb with excitement. Then the changes started to take hold.
From the waist down her skin started to itch like crazy as brown horse fur started to grow. Her huge slappable ass began to expand even more and change shape into a muscular horse ass exposing her throbbing anus. As the changes continued Katie couldn't help herself and began stroking her huge horsecock with both hands using her continuous leakage of precum as lube. The muscles all throughout her legs started molding to become more powerful and horselike. Her thighs expanded as they filled with muscle now looking more like the huge thighs of a horse. At that moment pain shot through her legs from the knee down and Katie fell over. She watched in horror and grunted in pain as her bones started to rearrange in her lower leg. Her feet started to shrink and harden until they were a sturdy set of hooves. Her legs continued to reshape until they resembled the hind legs of a horse. The pain died down and the wave of pleasure returned as something else unexpected happened. There was a familiar feeling of pressure above her rock hard horsecock. She continued to stroke her monster cock as a bump appeared above it. The pleasure wave intensified as a second horsecock started erupting out of her. As her new beast grew so did her balls until they were the size of cantaloupes, to accommodate her new additions cum flow. Katie's horse ass begged for something to be rammed inside of it. She slathered precum from her cock all over her hand and then proceeded to shove her whole fist inside of her throbbing ass. Her growing horsecock stopped growing when its size matched its dual tower of a cock at 2.6ft and started leaking a steady stream of precum. Katie then grabbed her new pole of meat and brought it to her mouth while sliding it through her huge DD tits. She then shoved as much of the flared head of her cock in her awaiting mouth as she could, giving herself a blowjob while thrusting her cock through her breasts. she returned her hand that wasn't hungrily fisting her ass to stroking her other horsecock. With so much pleasure being experienced at once her huge balls sent their payload rising up the shafts of her dual horsecocks. Katie gave a muffled scream as her cocks erupted with her baby batter, a huge river of cum shot down her throat and into her belly making it bulge with a huge amount of cum while her other cock showered her hot sticky seed everywhere covering her body. Katie felt a pleasure spread through her huge tits as milk squirted out of her nipples adding to the mix of cum all over her body. After minutes of a mind blowing orgasm Katie blacked out from pleasure.
When she woke up about an hour later she was lying on the ground of her apartment staring at the ceiling. "Was that all a crazy dream?" she asked herself. She looked over her mound of tit flesh and saw the bottom half of her body along with two deflated horsecocks laying on her stomach. She sighed wishing it was all a dream. She began to stand up learning how to walk on her hooves like a baby foal, she headed to the bathroom to take a shower. She looked in the mirror seeing her normal big breasted top half and then her lower two cocked stallion half. She wondered what in the world she was going to do about this and how she was going to hide herself in public. She stepped into the shower her hooves clacking on the tiles and began to wash off all the cum and milk from her body. She decided that she should probably go back to the magic shop and confront the swindling old man about what he did to her. Or she could call her best friend Susie and reveal her tragedy to her maybe she could help in some way.