You place your hands on your hips, moving them back and forth as you look down. You feel your strange new cock swaying inside its sheath, instead of atop your balls. It's bizarre, and looks silly on you, but damn does having a cock this big feel good.
You sep out of your pants, leaving them heaped on the floor and moving from toilet to sink to look in the mirror (and take a few seconds to rinse off your hands). Yup, still silly, but... damn.
You're not giving that up.
Instead, since you seem to now have the ability to edit realiy, you can change the rest of your body to match. You consider this idea, still shifting your weight from foot to foot. You'd been rather indifferent to "furry" stuff, but... well, maybe you'd been missing out. Or maybe your new second head was affecting your thoughts. But the idea of being a stallion grows on you, and you smirk as you make your decision.
"I am a horse man," you declare, folding your arms. "Big and strong, solid six-pack, barrel-chested. Big swollen balls to go with my giant horse cock. Irresistible manly musk. Just... irresistibly chiseled, hung, and virile."
You feel your body just... swell. You shoot up in height until you're over seven feet. Patches of brown fur break out all over you and spread until they cover you at the same time as you grow both more equine and more muscular. Your nuts fill with seed, your sack stretching and dangling, nudging further down your legs, plump and heavy with stallion spunk. The scent of them wraps around you as you grunt softly, feeling your virility and your libido skyrocket.
Your neck gets thicker and a bit longer; your face pushes out into a strong, blunt muzzle with flared nostrils. Your ears lift, poking up through your hair, which grows out and merges into a black mane running down your neck. Only your eyes remain relatively unchanged, though their dark green depths smoulder with a stallion's lust and dominance.
Your chest barrels out as you said; your pecs, traps and deltoids gaining size and definition until you look like a wall. Your folded arms bulk with muscle, making your stance truly intimidating. The fur on your hands turns black, and your nails thicken and turn into black semicircles that enclose the outer tips of your fingers, while the inside of your hands grow dark and leathery, almost like a thin callus.
Across your stomach your abs form a classic washboard visible through your fur. Your thighs expand into trunks, your butt swelling with muscles. A nub grows from your tailbone, and more black hairs sprout from it, swishing down the backs of your growing legs. Your calves also expand, and you feel them pull on your tendons as your feet evolve into a horse's, your ankles turning into hocks, and your toenails fusing, thickening and expanding around the balls of your feet, giving you a pair of massive hooves to support your impressive frame.
Tall, broad, well-muscled but not overdone -- your errant mention of "racehorse" has held true and for all your body's growth you still have a sleek look that says you're built for speed as much as strength. You're amazing, stunning, and you can do nohing but bask in your power, your perfection. Your cock fits you now -- your body having grown to complement it and your weighty balls, a stud from your upright ears to your solid hooves.
You unfold your arms to do some poses in the mirror, flexing your torso as you make your biceps pop. Then you feel over yourself, sliding your right hand down your sixpack to cradle your overflowing, naked package.
"Oh yeah..." You groan deeply as you feel over your stallionhood, closing your eyes in bliss. Encouraging your thick cock to push out a bit, shivering with the pleasure, the power of it as you move your fingers over the flared head. You draw a deep breath, relishing the expansion of your chest, then put your fists on your hips and stare into the mirror in admiration.
"Everybody who sees me wants me. Mmmff. Yeah. Wants me to cover them like mares and fuck them -- fucking break them."
Your cock emerges more. God you feel so powerful. You ARE so powerful. It hits you fully -- everything you said came true; everything you say WILL come true. You huff in a breath of your own intoxicating scent, then sigh gently.
What did they say about great responsibility? Having to be careful of what you say takes out a little of the fun, but... you don't want any broken hearts. You can only fuck so many people, and you don't want someone pining after you if you're not interested in them. You can afford to be generous.
"Well." You amend your previous statement. "Everyone who sees me lusts after me... to a manageable extent." You nod. And after all, you can always make individual adjustments when needed.
Then, in your moment of thoughtfulness, something more occurs to you:
"Ah yes... everyone is chill with me like this. It's normal for me to be a big, hung stallion-man -- nnngh -- and it's fine for furries -- heh -- like me to go around naked if we want."
There. That takes care of that. Now to get to the fun.