Dean clicked ENTER, quickly looking back up at Jeff, excited to see the changes begin. "How long will it take for you to change completely?" he asked, not seeing any immediate, visible changes.
"I set it to take five minutes." Jeff said, feeling a wave of heat wash through his body. "I can already feel... something. Is it hot in here? I feel like it just got REALLY hot!" he began stripping his clothes off, starting with his shirt. "Oh, look! I'm already growing fur!" Indeed, the boys could see that dark hairs were pushing out all over his torso, over his shoulders and down his arms.
"Have you been working out recently? You look freaking RIPPED, dude!" Dean pointed out, noticing that his friend's muscles were much larger than he remembered. His pecs, shoulders and biceps were rippling as Jeff bent to pull his shoes and socks off, and as he straightened Dean realized they were growing right before his eyes! Jeff looked like a body builder! "You're huge!"
With a shock, Jeff realized that he was definitely growing, already a head taller than he'd been moments ago. The heated sensation was building, both outside as the new fur thickened and inside as he felt his muscles stretching and expanding, bulking up beyond normal human proportions. His shoulders were enormous and he could feel his hips ballooning outward, rapidly stretching the boxers he hadn't been able to remove quickly enough. His neck, already abnormally thick with increased muscle, suddenly strrrretched, pushing his head to dizzying heights.
Dean had backed up, staring at Jeff as his changes progressed with his jaw hanging open. It was grotesque, watching a human body stretch and expand as if boiling from within, but at the same time he was completely enthralled. Jeff was making grunting sounds of discomfort, but he hadn't screamed or cried out - the changes must not be too painful. And how INCREDIBLE! That this tiny machine could change a human being into another creature, all with the click of a button! It was mind-blowing!
A tickling sensation had Jeff twisting his head on his elongated neck, now finding it surprisingly easy to look down his back to where a stubby tail had begun to form. Wispy black hairs were growing from it, drifting over his huge hips and buttocks as they pushed out and lengthened. Suddenly his pelvis tilted, and Jeff found himself falling forward, reaching out with his hands to catch himself on the stable's saw-dusted concrete floor. "Oof!" he grunted, feeling like he now weighed about a thousand pounds. "I guess I won't be... standing on... two legs again for a... a couple of weeks." His voice had deepened as his vocal cords stretched along with his neck, and he was finding it difficult to string a sentence together, his tongue feeling clumsy in his mouth all of a sudden.
His hips were higher than his shoulders, his arms not having grown long enough to match his hind legs yet, but he could feel something changing in his extremities, like his fingers and toes were stiffening, pushing the ground farther away as they fused together. His middle digits thickened as the others dwindled away, the arches of his feet stretching out, his heels rising to form hocks as his palms elongated and his arms rapidly stretched to level his back. His immense weight and musculature was now fully supported on rather spindly looking limbs, the huge muscles he'd grown having lengthened and stretched out to equine proportions.