“Hmm, the theory sounds plausible on paper...but with this weird Equestrian magic in play, it's hard to tell if it'll work.” Twilight said to herself.
“Twilight, are you STILL working on that crazy idea of yours? Just because I'm a dragon in Equestria, doesn't mean you can use the magic to change me into one here....even if it would be awesome to be a dragon for a bit.” a voice came from the doorway, as Spike walked into the room.
“I know Spike, but I feel it's my duty as a scientist to try! Now, would you mind giving me a DNA sample? Just a few hairs will do.” she explained. Spike just looked at her confused and put up one of his paws and nodded to it. “Oh right...paws, kind of hard to get the hairs off with no thumbs. Hold on a second.” Twilight said as she cut a few off with a pair of scissors.
“I hope you know what you're doing, there is magic involved...are you sure you should be doing this? At the very least call Sunset or someone over to make sure someone is here if something goes wrong.” Spike pleaded, though Twilight just continued to write equations down.
“Look Spike, I appreciate the worry, but it'll be fine trust me. I've quintuple checked the math and measurements. It's perfect.” she said proudly. “Plus you're here, you can get help if needed.” she continued.
Spike just rolled his eyes and agreed, knowing he wasn't going to win the argument. “ Fine...I'll stay in here with you while do it, to make sure.”
“Thanks Spike, I knew you'd understand!” Twilight replied as she began to work. She mixed a few liquids together as they began to bubble. “Now, just have to add the hairs and a bit of magic from this.” she said adding the hair, watching them dissolve quickly. And then slightly opening the magic storage device she had in the Friendship Games, letting what was left of the magic into the beaker.
At first it seemed normal, but suddenly it started to bubble over the edges and turned a deep purple in color. “Umm, is it supposed to do that Twilight?” Spike asked in a worried tone.
“No it's not...I don't understand what went wro...” before she could finish the sentence, the beaker exploded, filling the room with a strange purple gas that both Spike and Twilight breathed in. “Sp-spike! Are you...coughs....okay?” Twilight asked, to no answer. Unbeknowest to her, Spike was undergoing a rapid change, still a dog, but now the size of a husky or German Shepard. “Spike! Hello!” Twilight yelled again as the gas cleared.
“Yeah, yeah...I'm fine!” he answered but his voice seemingly deeper. “I told you it wouldn't work, you're lucky nothing happened.”
“Nothing? Well your voice soun...oh something happened alright. You're still a dog, but you're a lot bigger.” Twilight explained.
“I-I am? I AM!!” Spike looked down at himself, seeing his new body. “W-wow...guess your crazy experiment did something after all! Thanks!” he sad before running out of the room to test his new body in various ways.
“ Thanks I guess...hmm, why didn't it work like intended?” Twilight thought, but shrugged it off and decided to leave for tomorrow as she had been in the lab for about four hours already today. They went on with their day as normal, though they did have to make extra room for the new body size of Spike, all the while not realzing the gas was slowly changing Twilight's DNA into a canine one, the reason it had worked so fast on Spike was that he was already a canine. Finally the night came, and with it sleep; this is where Twilight's change began.
She had started to sweat during the night, odd dreams filling her head, one's of the new Spike mounting and mating a female, though asleep the dream was vivid, she slipped one hand down into her panties as she rested, panting as she subconsiously played with herself, “ Ah...ah yes...mate me, I'm a good girl!” she kept repeating until she finally came and even though she didn't awake, her dreams subsided and her fingernails grew a bit sharper and black during the night.
The morning came and Twilight woke up to a big mess in her bed, but instead of being embarrassed, she acted like it was natural. She even took off her remaining clothes and threw them aside. “Eh, I'll wash everything later, plus those clothes...wearing them felt really odd, oh well. She changes had halted it seemed, but that quickly ended once she walked into the living room and saw Spike licking himself, her walking in just as he finished and came everywhere. “Sp-Spike...oh my!” she said under her breath before walking out of the room quickly back into her lab as she felt an enormous heat building. “Wh-what's happening to me?!!” Twilight asked herself as the gas vamped up speed, causing her to start panting, as her tongue grew longer and wetter. “M-my twongue?! It looks like a dogs!” she said, as the heat gets stronger, causing her to lean against the table. While all this is going on, Spike had finished licking his seed up, not wanting Twilight to know what he did, not aware she saw him, after he went out the dog door, to run outside a bit. As she leans, she raised her butt up instinctively not knowing why, but as she looked back a tail was growing rapidly and before she knew it , she was the owner of a black and purple husky tail.
“A-a tail now?! Arf can move it so easily.” she said almost mesmerized. Moving it around to see how flexible it was, not noticing the arf she did. “So flexible...I wonder if Spike would like it.” she asked herself as her ears shifted, moving to the top of her head and becoming pointed with her hair fusing onto them as fur.
The recent change, allowed her to hear Spike running outside through the window, hearing him made her heart race as she started panting again and fell onto her hands and knees as one hand reached between her legs just like the night before, as she masturbates thinking of Spike, fur begins to spread over her body as her feet reshape, her big toes shrinking and moving into dew claws and her other ones getting stubbier and the nails sharpen into claws. She's too lost in the thoughts of Spike to realize her hands are following the same fate, her thumbs quickly formed the front dew claws and her fingers grew shorter and fatter becoming front paw. She didn't notice until one of the new claws cut her thigh, trying to finger herself to no avail with the new paws. “ARF!!” she yelped as she cut herself.
“What was that? It sounded like another dog in the house...odd.” Spike asked himself, running back inside. Before he made it back in, Twilight had come back to her sense, almost fully covered in fur from her neck shoulders down as her breasts shrink rapidly, as three more rows of canine teats take their place. “I-Arf turrrrning into arf dog?!! No bark...woof...can't be...the gas?! Arf have to rrrrreverrrrrse it! Let's …..my hands!!! Arf can't grrrrab any wooftensils. Bark need he...” she was cut short when Spike came into the lab.
“Twilight what's going on I heard scre....aming....what in the world?!”
“Sp-Spike...the arf woof...gas from yesterrrrrrday.” she tried to focus, but the object of her recent lust was right before her, looking at him, her back snapped into place, becoming one of a four legged animal, as she got up and walked to him. “Rrrrrrrrrr, so hot....and bark....big rrrrrrrr.”
“Umm....Tw-Twilight, are you okay? What's gotten into you?” Spike asked, as he was in a mix of arousal and nervousness.
“Mmmmmmm, arf saw you earlier licking arfself, arf woof you in me rrrrrrr.” she said plainly, as her vagina changes shape and spots to under her tail as its scent changes to a bitch in heat.
“ You saw that?! I umm...uh....sniff....sniff.” Spike tries to answer, but Twilight's new scent has him reeling, as his cock begins to come out of its sheath. “Th-that smell...can't resist....GRRRRRR!!” soon, the gas inside Spike wells up another change, as Spike stands up bracing himself as his body changes again. Growing to a larger, more fierce size as his privates also changed, growing larger. He had now turned into a wolf right in front of Twilight.
Seeing the change was enough to fully get rid of Twilight's human mind entirely and seemingly Spike's too. Twilight turned around, presenting herself to the wolf whom takes no time at all to mount her. As he does, she remembers the dream and revels in how its a reality now as her face changes as she gets fucked, pushing out in a husky's face as her teeth sharpen into fangs and her tongue rolls out in bliss. The two continued to mate for about ten minutes, Spike thrusting hard and fast into Twilight until finally he howled loudly into the air, shooting his seed into her, making her bark loudly as she came as well.
A few minutes passed with them knotted together, before Spike was able to get out of her. Despite the mating being done, the two didn't return to normal. After a while, Fluttershy came to the house to find the door open but neither Spike or Twilight anywhere to be seen, just two sets of paw prints leading into the nearby woods...
