The thunk of metallic feet pounding rapidly up the stairs sent the Professor wincing, ears folding against his head. Not now, not now! He was so close to a major breakthrough…his energy management program was near perfection! Just a few tweaks here and there to a script or two, and each of his creations would be able to run at unparalleled efficiency! Converting electricity to matter, matter to electricity, repairing themselves at will, able to alter themselves at will, adapt to any task, elevating his works to the greatest creations the world had ever-
“Proffeeeeeessoooooooor!”
The brown-furred, middle-aged lapine groaned, shutting his eyes as that singsong voice accompanied the hop-skip of metallic boots against the lab floor. A sigh pulled its way from his lungs, his train of thought exiting the station of his mind as the distraction that was Cobalt peered over his shoulder. The half-robotic bunny cheerfully beamed down at the slightly-shorter male, her streamlined, eponymously-colored frame bouncing in place, the whirring of servomotors accompanying her saccharine, high-energy questions.
“Whatcha doin’ up here? Wanna hang out? Or take a trip? Or try out something new and exciting and experimental-y on me? Huh?”
The Professor couldn’t help but smile up at the bouncy cyborg. She’d been one of his very first creations and, though he’d rarely be caught saying something so sentimental, she was his favorite. He sighed and shook his head, tapping a few more keys.

“Cobalt, I really can’t right now. I’m nearly done with this beta program, I swear! In just a few more hours-“
“Awwww!” That whine cut him off, the robo-bunny’s lower lip jutting forth and trembling with calculated frequency, red-irised eyes widening down upon him, “But you said that yesterday! And the day before! C’mon Professor, don’t you wanna do something with me?” She leaned her metal frame against his chair, fingers drifting up to play with the set of brown ears atop his head, “Something more interesting and fun than sitting at a boring ol’ computer desk all day?”
He shook his head, reaching up to gently but firmly remove her robotic hand from his ears, “I mean it this time! I’m nearly done perfecting this program! Just,” The brown furred bunny sighed again, tapping a few more keys, saving what he had onto a tiny datadisc, holding it up before his pouting creation, “check this program over for me, will you? By the time your diagnostic is done, I ought to be finished! And don’t touch anything in there.” He warned, raising a finger, “This is a very delicate piece of work, and if you start running it without me we could both be in a lot of trouble. Understood?”
For a moment, Cobalt seemed ready to try pouting at her creator one last time. His firm stare seemed to dissuade her from the notion, however, and with a return of her cheerful smile she nodded rapidly, plucking the tiny disc from the Professor’s fingers, “All right! But you better have something fun in mind for when you’re done!” She added as she skip-hopped back towards the doorway. It hissed shut as she pounded back down the stairway, and with that, the lab was silent once more.
The Professor let a single chuckle escape from his lips, shaking his head, “That girl…” He turned his head back to his scripts, squinting and leaning forth, “Now where was I…?”

To anyone else, it would have seemed genius, marvelous, astounding. But to Cobalt, whose life with the Professor was all those things and more on a daily basis, it was all rather same-y. Some code regulating the matter-energy converters he had installed over a month ago, the ones he’d begged her not to attempt using “until he was ready”.
“Hmph…” She muttered as the lines hurtled about her head, plopping down on the couch in the living area below. As if she couldn’t decide when she was ready! There were inside her, after all! Each converter linked to every set of conduits and port in her shapely blue metallic frame, all interacting with the boundless power source lodged somewhere in her smooth black belly. And the thought of making just about anything from the electricity she drank from at each meal and during the night was mind-boggling. Imagine all the things she could do with the ability to conjure tools from thin air, to adapt to any situation! Now that’d get the Professor out of his chair and doing something fun again!
A grin burst onto her fur-coated face, a rising melody of a giggle erupting from her throat. She wouldn’t have to tweak anything…she’d just grab a little power and try it out! Reaching forwards, she plucked an unused set of batteries from the coffee table. Tearing the tiny treats open, she popped one into her mouth, the contacts built into her tongue grinding up against each end as she tumbled the thick cylinder end over end. The sharp, sweet taste of power burst through her grid, an uncontrollable moan of delight escaping her as she experienced the most minor of power surges. With a simple thought, she ran the thousands of lines of code in her mind’s eye. And suddenly, that power surge was gone, drawn away from her battery, towards the converters.
It started as a tingle, a warm, delightful spread across her sensors just as the battery died between her jaws. She spat the liquid conductor-coated cylinder out, groaning and shifting upon the couch as her vision shifted ever so slightly, enough for her to recalculate her rangefinder data. Her point of view simply wasn’t possible, given her specifications and seated position!. But there she was, looking upon the world from exactly 1.1 inches higher than normal.
Her frown of confusion burst into a wide grin as she reexamined each script. The Professor was right; the program wasn’t finished. And in their beta state, the matter converters only had one way to utilize the energy she could feed them: by adding it directly to her frame, building upon her specified dimensions, expanding them proportionally with exacting precision. By growing her.
Cobalt let out a delighted giggle. This was going to be fun.
She snatched up the batteries like candies, popping the rest of the package into her maw and suckling upon the crackling flow of delicious electricity. Dead shells thumped upon the carpet as inch after inch clambered upon her height, her mass expanding delightfully upon the couch. Every slip of the cushions against her thigh sensors sent her giggling, the growing creaks of the furniture against the cyborg’s proportionally expanding biology and technology exhilarating. The things she could accomplish with a larger body, the wonder and awe she’d inspire, how proud the Professor would be with his greatest creation literally ascending to new heights sent tantalizing shivers coursing through the neural net in her spine. The last battery popped from her lips, and the six-foot-six bionic bunny lurched to her metallic feet, letting the couch groan with relief. She needed more!
Her eyes fell to the outlet, the one tucked just behind the great, ornate mountain of an armchair the Professor clambered into with her on cozy, chilly winter nights. The entire room shook as her knees hit the floor, the weight of the seven-foot-something cyborg bunny swelling exponentially as every ounce of electricity fed the expansion of flesh and fur, alloy and  servomotor. A flick of an index finger brought a charging probe to bear from  its tip, thin tendrils splitting from each other to jab themselves into each slit. And where the tiny batteries were mere of delectable energy, the outlet sent gigantic, raging rapids of alternating current frothing and surging through each conduit, every pathway in her neural net, threatening to burn out her once-spacious battery with the gargantuan pulse. And then, with a single, instant thought, the converters increased capacity, and her hunger grew to match the oncoming flood.
Cobalt couldn’t help but moan as she drank kilowatts down through that single digit, hunched against the carpet fibers as they shifted and slid against her armored shins, the unyielding expansion sending delightful tickles arcing from each sensor. With her ears folded back she began to writhe, limbs splayed on the carpet, brown locks tumbling and rippling with each turn of her head, each nuzzle of furred cheek into the dwindling field of fibers. So much power, enough to send her robotic frame into flames from a catastrophic overload…and yet it was dwindling by the second. She needed more!
The armchair skidded and slammed into the far wall in the face of a mountain of metallic rump. The flex and stretch of powerful legs sent the couch toppling over in a thunderous crash, the massive thump of limb against floorboard sending the entire home shuddering as the small of her back graced the ceiling….
The keyboard itself began to tremble beneath his fingers, and the Professor loosed a snarl beneath his breath within his rattling laboratory.
“What on earth is she doing down there?”
The brown-furred rabbit winced as a thunderous crashing sounded beneath him, getting to his paws, slender fingers clenched into frustrated fists while his ears drooped upon his shoulders. This wasn’t like Cobalt at all...she was hyper, loud, clumsy, maybe, but she had never just blatantly ignored his request! He’d have to do something about that girl. But as he began to march towards the door, the center of the room flexed, sending him stumbling backwards in shock. The tile crackled and split, workbenches spilling over as a gargantuan head blasted skywards, nearly splitting the second-story ceiling as brown locks tumbled onto the rubble-strewn floor, blue-tipped, white-furred ears flattened against the plaster ceiling, and a massive set of red, round eyes peered down a snout bearing a wide, delighted grin he knew all too well.
“C-C-Cobalt?!”
The bunny girl’s gaze focused upon him as the house crumbled around her shoulders, that once petite frame sending lab benches tumbling down into the collapsed basement in a series of mighty crashes, the massive clutter of bubbling flasks and half-finished prototypes shattering in an eruption that set the utterly baffled bunny cringing. A deepened, delighted giggle erupted from the gargantuan robo-bun as those massive eyes settled down upon her puny creator, unknowing or uncaring of his slack-jawed terror.
“Whoah! This is awesome!” Her squeal nearly deafened him as it rattled the doomed suburban home to its core, walls quaking from every shift of the slender cyborg’s immensity. “You should’ve told me that program you were working on was so cool! Matter-electricity conversion’s gotta be the coolest ability you’ve ever given me!” She knelt upwards, ears flattening against the second-story ceiling with a heavy whump! “This even beats rocket boots!”
“B-but, y-you weren’t…y-you weren’t supposed  t-…!”
Before the Professor could work his trembling lips into shapes resembling syllables, Cobalt thundered on, her deepened voice overflowing with excitement as her head began to crack the ceiling and roof beyond, splintering beam punctuating every other word, “Run it? But how could I just look at something so fantastically, incredibly, mind-blowingly awesome? Just imagine all the cool stuff I could do for you when I’m totally supersized! Going anywhere, doing anything…and with all that power, you wouldn’t even need this lab! I’d be your greatest creation!”
She beamed rather proudly, enough to send an instinctual, brief burst of pride into the baffled Professor’s heart…before she barreled onwards, that is. “And every time I come into contact with a source of power, the converters’ll handle the overload and make me even bigger!” She frowned abruptly, sending the middle-aged brown bunny upon the disintegrating second floor scrambling back as her index finger lurched upwards with a waggle, her charging probe releasing the outlet she’d been using, another with a chunk of the living room wall, at his feet, “Too bad I can’t fit my probe into a normal socket any more…I’m too big!”
Then those window-sized eyes widened, and the great glint in their shimmering surfaces sent the coldest of shivers down the dumbstruck rabbit’s spine, “I’ll just have to go looking for an alternate power source! I’m sure there’s a few things around our neighborhood that’ll do!” Her gleeful, bubbly laughter rolled forth like a tidal wave as she added an afterthought, “Ooh, the whole town’s gonna be amazed when they get a look at me!”
With a shift and a low grunt, Cobalt lurched upwards on her knees. With an eruption of heavy crackles, the roof of the once-impressive two-story home broke free of its walls, and those walking the sideways around their block were treated to the sight of their friendly local cyborg bursting out of the spacious homemade laboratory like a cat from a cramped cage, the roof tumbling down the slope of her ears as thick brown locks tumbled into place around her shoulders, the shell of a home only waist-high to the gargantuan  lapine as she announced her presence with a groan of relief amid thunderous crashing. The rumble of massive servomotors accompanied her mighty stretch, her giggle rolling forth over the remaining rooftops as her eyes fell back to her creator, safe, albeit trapped, upon the second floor of their home. With a wink, she waggled her fingers down at him, thundering once more.
“Don’t you worry about a thing, Professor! I’ll find myself some more power ASAP! I’ll be the best cyborg you’ve ever seen!”
Though the whole house threatened to collapse around him, the trembling, awestruck Professor still attempted a shout over the clank and whir of metal and servomotors lurching into motion, crying upwards as Cobalt raised a mighty foot high into the air, stepping over the walls as he shouted,
“N-no! Cobalt, wait, you c-can’t just-!”
THOOM! The force of her gargantuan footfall was nearly enough to send the ruptured second floor collapsing in to the pit of debris his once-beautiful home and workplace had become, sending the poor lapine clinging to his desk as Cobalt stepped forth, the sound of the front lawn being pulverized into a crater accompanied by a second explosive footfall, each impact echoing off the fragile walls. As the quaking fell into a thumping rhythm, the Professor managed to stumble to his paws, thin chest heaving with heavy breaths, his eyes wide as the truly massive implications of his work dawned in his mind.
He’d intended for the program to be the perfect upgrade for Cobalt, to give her the ability to do anything and everything with a jolt of electricity and a single application of expert programming, and just as he’d hoped, the conversion process had worked perfectly. For her to swell to such heights from a mere household plug’s flow of wattage was beyond his wildest projections, the sheer amount of matter produced from such a relatively small amount of energy truly mindblowing. The fact that its default seemed to be to add to her own mass was of little consequence; without a defined output specified by her brain, the ability to handle such power surges through such a creative method seemed logical, almost ingenious. And, like the eager, proud creation she’d always been, Cobalt was all too delighted to show off her new ability.
The Professor burst from the backdoor of his crumbling home, fumbling for his keys as he looked up to see the cyborg bun thundering away in the distance, her thunderous giggles travelling on the wind like deep, bubbly waves. She’d turned herself enormous, terrifying, a massive danger to him, the town, the whole region, even…and yet, deep down, a flicker of pride managed to calm his nerves as she smashed up the suburban roadways beneath her mighty tread. He’d always known she’d be the one to really hit new heights…now if only he could bring her down from them!

The cacophony of crackling concrete, the deafening pound of alloyed paws the size of sedans, and the bassy, rumbling quake each of her steps sent down the street and into each and every suburban home beneath her vision culminated in a booming giggle that rolled flat over the smattering of shrieks that rose up to greet her magnified voice. She knew she’d been impressive before, a miracle of scientific progress and careful craftsmanship; and yet, none of it compared to the sensation of roadways crumbling beneath her gait, or the grin-inducing sight of her quaint neighborhood reduced to model stature.
“Oooh, everything’s so cute!” She squealed with a deafening intensity, brown locks fluttering in the breeze as she giddily towered above. When the dozens of furs in their homes took one look at her titanic frame and ran in terror, she merely loosed a bubbly giggle in their wake, calling out playfully as she made her way up to the intersection.
“Aww, don’t run! I’m not gonna hurt anyone! I’m-“
The dying screech of a parked car beneath her treaded sole sent the colossal cyborg flinching, her foot lurching off the automobile she’d flattened like a tin can. A flush and a weakened laugh escaped her, and she meekly shifted the rendered pile of debris to the emptied sidewalk, “W-well, I-I’m usually careful…heh, guess I don’t know my own strength yet!”
This, however, didn’t seem to pacify the fleeing crowds that had flooded the streets, and the big bun’s ears drooped as her mood plummeted at the momentary bout of negativity. Her thunderous steps lost the boundless energy she’d added her titanic frame, each impact of paw on asphalt pounding craters a mere fraction of the size she’d made on her initial romp down the street. A breathy gust of a sigh rattled the treetops lining the ravaged roadway, her downturned gaze and momentary frown shifting from their lush foliage stretching to meet her shoulders, to the two-story rooftops just below her chest, to the power lines strung about near her waistline…
“Oh!” Cobalt burst back into a wide grin, her fist reaching down to clench around a transformer perched atop its pole, a crackling surge of electricity sending a delightful tingle up the conduits within her fingers, “Oh, I can’t believe I missed these! These’ll be perfect power sources to draw from!” She giggled to herself, ignorant of her musings booming for blocks around, “At least, until I get too big for them, too!”
As her converters drank from the transformer crumpling in her metallic fist, another thought popped into her head, and with a thunderous lurch of motion the titanic metal bun thundered through the intersection, her swelling fingers clutching the electrical tether of the power lines. Fifty feet became sixy, then seventy, and the pound of her feet swallowed up both lanes of the street, blasting asphalt to dust beneath the thunder of delightful laughter overhead. Stoplights met her thighs and snapped as her thunderous footfalls blasted through the intersection, startled traffic screeching to a halt as her mighty steps overhead grew larger, longer, and heavier.
“And then, all I’ll need is a bigger power source!” As her pull on the lines began to wrench their poles clear of the ground she giggled, a map flashing within her mind’s eye, “And that should be right at the end of these lines!” The earth was shattered as the titan bun launched into a skip, the trail of posts and power lines ravaging her cratered wake as she neared her destination, swelling up into the skyline with each ampere of power...

He’d spent nearly an hour navigating the cratered streets, wedging his tiny sedan through piles of debris and rows of crumpled cars once parked in the streets, thunderous quakes and the occasional deep, booming giggle rattling the very earth. The damage she’d managed to wreak in her path was truly stunning, even given her gargantuan scale, and it was all the Professor could do to keep from marveling at the shattered roads, and the power lines snapped from the earth like so many toothpicks from a soon-to-be-devoured sandwich. Cobalt had clearly taken to her new size and strength with gusto, though she’d clearly completely ignored any sense of delicacy. At least she hadn’t plowed through any buildings…now if only he could catch up with-
The sight of a titanic shape above the treetops at the roadside sent the Professor’s eyes wide, and with a yank on his wheel he followed the snapped powerlines down a final left turn, up a long stretch of roadway. His heart dropped through the floor of the car as he belatedly realized his creation’s destination, and with a slam of the breaks he skidded to a halt outside the gates of the power plant, stumbling from the car as a mere shift in colossal weight sent the earth rocking.
There, wedged between two titanic smokestacks, Cobalt boomed a giddy laugh, its volume sending the puny Professor’s ears flat against his head as it rolled like thunder over the surrounding treetops. She’d gone from house-sized to hundreds of feet, nearly surpassing the great stacks to her sides even while crouched. The crunch of concrete against metal sounded as a gargantuan robotic hand clenched around the central complex, great, shining digits crumbling its walls, titanic, flashing bolts of lightning hurtling up her arm, into her titanic frame, setting her crimson eyes literally alight as she clutched a snapped tangle of power lines in her other fist, drinking deeply as her whole frame buzzed and glowed with electrical discharges, her monstrous, grinning visage blotting out the sun as she spotted her utterly speechless onlooker far below.
“Hee-hee! Told you I’d find more power, Professor!” Her voice erupted from that gargantuan smile, bubbly, delighted tone rippling the very atmosphere as her vast, brown locks bounced with every earthshaking motion she gave, “And look how tiny you’ve all gotten! Hee, I’m gonna have so much fun when I’m done drinking up all this delicious electricity…” She groaned softly as a great bolt of energy zapped its way up her arm, her giggle echoing in the ears of her awestruck creator as she leaned high overhead, her voice the thunder accompanying the great bolts of lightning that sent her towards the skies.
“Mmm, forget showing me off in town…when I’m done, the whole world will be able to get a good look!”