Thanks go out to @the-craftsman for this idea!
Something was wrong. Perhaps it was easy to argue that everything about this situation was wrong but Daniel “Gizmo” Gibzon was choosing not to think about that. He had his reasons for wanting to become Stiles Stilinski and he didn’t care just how wrong people might think he was for wanting to steal another person’s life. What he did care about was just how strange his body was now feeling, and the strange worry in his gut that something had gone awry.
Daniel had been interning at Deaton’s animal clinic for the past several months with the intention of going on to veterinary school afterwards. He had always had a clear goal for his future but that had been muddled by his introduction to Stiles. It had been his colleague, Scott McCall, that introduced them and even though Scott might have been considered the more happy-go-lucky handsome jock type considering his role as a lacrosse star, it was Stiles that captured Daniel’s attention.
Stiles was everything that Daniel wanted to be. He had risen from being an invisible nerd in his sophomore year to a handsome senior with a good sense of humor, more popularity than he realized and beautiful people pining after him around every corner. Maybe Stiles didn’t see it but even Daniel noticed the way Derek Hale stared at him when his back was turned, or the lingering looks Lydia Martin made when Stiles’ attention was otherwise occupied.
In no time at all Daniel became obsessed. They both had odd nicknames, only Stiles’ was self-picked and his own hadn’t. In fact it had originated from bullies and it had taken a while for “Gizmo” to really stick as something that didn’t have to be cruel. He envied the fact that Stiles had always been able to overcome the adversity thrown at him by bullies like Jackson Whittemore. He couldn’t help but stalk all of Stiles’ social media profiles and even occasionally follow him at school, taking note just how often the boy would disappear with his friends. Where was he going? Why were they keeping so many secrets? It was peculiar to say the least.
Lots of strange things happened in Beacon Hills and Daniel wasn’t exactly clueless to it all. He’d heard rumors of werewolves and witches existing in their city and even their high school, and he was certain that some of the concoctions Deaton used to soothe and relieve the pain from the animals weren’t simple medicine. A little digging all but confirmed they were potions and once Daniel had been exposed to their existence he all but fell down the metaphorical rabbit hole. He saw an option to finally get what he wanted and even if he was out of his depth there was no way he would be able to stop himself.
With no idea where to look and not wanting to alert his boss to his true intentions, it took some time for Daniel to find exactly what he wanted. It was only by chance that the solution fell into his hands - a grimoire that had been stolen from the infamous Hale vault and sold on what constituted as Beacon Hills’ black market. The grimoire was written in a language that he didn’t understand so Daniel was reliant on the hardly descriptive images on each page. When what looked like an image of one person turning into another, he knew he’d hit the jackpot.
An assortment of sketches below seemed to detail the ingredients needed and although Daniel couldn’t be certain that he had everything he needed, he was surprised by just how many of them he found hidden in various parts of Deaton’s clinic. There’s no way he’s not involved in all this crazy stuff, Daniel thought. Still, he wasn’t about to announce to his boss what his plans were because he knew to expect outside interference. The last thing he wanted was for Scott or - even worse - Stiles to find out!
The only ingredient Daniel struggled with was a strand of hair from the person he wanted to become. There was no immediate way to get a piece of hair from Stiles and so he was forced to wait until the next time the boy appeared, talking to Scott in hushed whispers. Much to Daniel’s relief the other pulled his jacket off and threw it down on the counter before leaving to consult Deaton on something. Seizing the opportunity, Daniel reached over the jacket and after a few moments of quick inspection, pulled a strand of dark brown hair from it and dropped it into a glass tube. With that he had everything he needed to make his wildest dreams come true - or so he thought…
Despite still being unable to read the grimoire in its strange ancient language, Daniel felt optimistic as he combined all the ingredients and the hair from Stiles’ jacket into a small flask. It sparkled in a manner that no natural concoction ever should and even not knowing much about magic, Daniel was relatively confident that he’d done everything right. His heart was pounding in his chest, thrilled at the prospect of getting the body and life he’d dreamed of for months.
The moment the potion crossed his lips, a shiver rushed down Daniel’s spine. He had anticipated this moment for so long and as he felt his body begin to react to the magical substance now spreading throughout him he felt as if he could cry. The physical changes began almost immediately with his legs growing longer as he gained several inches of height and catching him by surprise at just how different everything felt when he was even the smallest amount taller.
Watching in wonder as his feet grew several sizes, Daniel wasn’t at all surprised when his cock started to react, causing the crotch area of his jeans to tent. He’d always had a thing for feet and had purposefully taken off his shoes so he could watch them grow bigger. The fabric of his socks were pressed tightly over them now and he was already imagining the dusting of hair they had on top of them.
It was only when Daniel’s upper chest started to expand, stretching his white t-shirt with the undeniable shape of two firm pecs that he began wondering if he’d done something wrong. Stiles was lean and gorgeous, not muscular, so why was he growing pecs? Even his stomach was toning up, giving him abs that he couldn’t help but trace his fingers over once he had pulled his shirt off.
“Wha– what?” he gasped in a voice that seemed to be all over the place. He didn’t sound like himself but it didn’t sound like Stiles’ voice either… What’s happening to me? He was so sure that he’d gotten everything right! “This isn’t right!” he gasped, flinching as his voice peaked for a moment. Pull yourself together, Gizmo!
Stumbling forward, Daniel winced as he felt the tightness of his jeans around his thighs and crotch and realized that both had grown considerably larger. He wasn’t seeing Stiles’ skinny frame when he looked down, nor even Scott’s toned-but-relaxed frame. His body looked like it belonged to a high school jock and Daniel was furious. How had he managed to get it wrong?
“I need to fix this,” grunting in a much deeper voice than he was used to. In fact, it was a familiar voice too and that raised his inner fear because it wasn’t a voice he was too fond of hearing. Staring down at his hands and newly muscular chest, Daniel found his heart beginning to beat faster. No no no, this really can’t be happening…
Pulling the cell phone out of his pocket, Daniel quickly activated his front-facing camera and gaped at the face of Theo Raeken staring back at him. What? How?! Theo was a relatively new arrival at school and while Daniel didn’t know him all that well, he knew that Stiles didn’t like him so clearly that meant that Daniel shouldn’t either.
Oh no, Stiles is going to hate me now! It was all Daniel could think about - for several seconds before a rogue thought about how nice it felt to have actual physical strength for once invaded his mind.
The thought was particularly perplexing considering how little he had cared about physical dominance in the past. He had been attracted to Stiles because he had a funny personality to go with his gorgeous and lean body, not because he was some meathead jock who substituted their brains with brawn.
It took Daniel a somewhat embarrassingly long time to realize that the hair he had plucked from Stiles’ jacket had been Theo’s and not his crush’s. He’d always prided himself on being relatively bright - your best friend being your Kindle eReader kind of helped in that case - but it had seemingly escaped his mind. Besides, how was he supposed to know he had the wrong person’s hair?
“I’ve got to find a way back,” he decided, surprised by how reluctant he was to look away from Theo’s face in the camera. He supposed that despite Stiles’ dislike of him Theo was actually pretty good looking. In fact Daniel would venture as far as saying he was sexy in a ‘bad boy’ kind of way and right now that was him! It was taking a lot to get his head around that.
Stiles will probably know how to fix this, Daniel realized, thinking of every time he’d watched his obsession sneak away from the school with McCall’s pack. Wait, pack? Where had that thought come from? Why wouldn’t he just call them Stiles’ friends? What the hell was a pack?
A six-pack, duh. How could I forget these sweet abs? Once again foreign thoughts invaded Daniel’s mind, all spoken in Theo’s voice and prompting his cheeks to flush in embarrassment. This wasn’t like him at all! He couldn’t deny that the abs were most definitely ‘sweet’ though and grinned as he tilted his phone down to take a picture of them. He didn’t even think twice about it.
Once he had taken one selfie, the proverbial floodgates all but opened and Daniel began taking picture after picture, flexing in each of them. He didn’t even have to think about how to pose as it all came naturally to him and with every passing minute all the anxiety he’d felt about his potion mistake faded away to be replaced by cocky thoughts of how damn good he looked!
As the minutes passed, the teenage nerd thought of himself less as “Gizmo” and more as Theo Raeken. He laughed at the thought of ever having been obsessed with a scrawny loser like Stiles Stilinski because why would he waste his time on that nerd? Sure, maybe he could seduce him and get some good head out of it but he had plans for bigger and better things.
Thoughts began filling Gizmo’s mind that he never would have considered before - thoughts of Scott McCall squatting in tight workout shorts or slowly rubbing his own pecs as he laid on top of his bed sheets. Daniel’s newly expanded body was quick to react and he felt totally overwhelmed by the brand new emotions and thoughts he feeling.
The new Theo’s rapidly decreasing intelligence failed to understand exactly what had went wrong. In his rush to create the potion and become Stiles he had neglected to even attempt to translate the instructions. Those very same instructions informed the reader of which order to put the ingredients in and how many times it had to be stirred. Without that, Gizmo had been exposed to volatile magic and it had totally consumed him!
After taking what must have been his hundredth selfie, Theo paused to look around. Why the fuck am I at Deaton’s clinic? he wondered. He needed a change of scenery for his next batch of shirtless selfies - or hell, maybe they’d just be naked ones! Maybe he’d taunt Stiles with a few nudes and then screw him around by fucking Scott instead. Or hell, maybe he’d let Scott fuck him. He had nothing against studs like McCall getting comfortable between his cheeks, after all!
As he turned around to grab his shirt and get the hell out of there, the young chimera paused. He could have sworn that there was supposed to be a book behind him, only now there was nothing there. A big black book with a bunch of nonsense written in it that he’d been joking around with just a few minutes before. He hadn’t imagined that, right?
“Aw hell, who gives a damn?” Theo sighed before grabbing his shirt and getting the hell out of there. He had some more flexing to do!