Beast's mind was racing almost too fast for him to keep up. He had set out to make a potion that would give the X-Men a temporary edge, boosting their mutant abilities for a short time. He had designed it to only increase the potency of the X-gene 50% at most, but a self-administered test had revealed he had gone far beyond that. In just a short time, he had more than doubled his weight and gained over two feet in height, all muscle!
There was no telling why he had taken to the potion so well or how long he could expect the effects to last. In the meantime, he had to learn how to navigate the lab with his much bigger body. As he thumped from station to station, the big blue mutant was constantly misjudging his relationship to the space, knocking tables over with a casual bump of his hips or accidentally crushing his lab equipment with a paw that felt like it had doubled in size. He had to lean over quite a bit more to see anything below the barrel of his chest, and everything he touched felt...small and fragile. It made the going difficult, but he was determined to study this while he could. Strike while the iron was hot, as it were.
However, as the minutes ticked by Dr. McCoy felt as if he couldn't ever quite get comfortable. Just when he thought he could reasonably navigate his own bulk he felt bigger, bulkier than before. When he thought he knew how gentle he needed to be with his sensitive lab equipment, he found that his light touches were still breaking thin glasses, petri dishes and microscope slides. His pens and datapads felt even lighter, and his massive fingers were shockingly thick compared to the display settings he had grown used to. He felt himself growling under his breath before too long. Being this big was getting to be a pain.
All the time there was a small buzz in the back of his head, this current of electricity running through him. Unnoticed by Dr. McCoy, the potion was still at work, making the previous changes permanent while introducing new ones. Steadily, surely, Beast was growing even larger and stronger, his weight ticking upwards with every breath. And, when his body grew thick enough that it couldn't possibly hold much more muscle, his height would inch upwards and the process would start again.
Despite his discomfort, he tried to take measurements, study the effects of the potion on his system and extrapolate data based on that. When he felt himself having to curl further against his own bulk to see inside a microscope, he finally figured out that something was up. He rose to his height and took a good look around the lab, noticing how much...further down everything seemed. And how much his immense blue-furred body took up his vision whenever he glanced in that direction. His shoulders were threatening to swallow his neck completely, and his chin brushed the pelt on his chest. He'd have to bend at the waist to see his own feet.
"Oh my...." he rumbled, realization slowly dawning. "I don't think the potion is quite finished with me yet."
The enormous mutant thundered back to the weighing station and waited for the computer to acknowledge him.
"DNA recognition match: Dr. Henry McCoy. Welcome back, doctor. I see that you've gained even more weight since we last spoke. If this keeps up, you're going to weigh the same as a small car by sundown."
"Betsy my dear, that's why I'm here." Hank decided to side-step the computer's wit to get right down to business. "Can you tell me how tall I am and how much I weigh?"
"Certainly doctor." There was a pause. "At the moment..."