Mark regretted his actions, but this was easily undone! He had a whole box full of transformations with which he could restore Greg! He held his hands out, and Greg stood still as Mark stumbled into the kitchen and retrieved the box of vials. He rifled through the box and located the Man Vial he had taken himself earlier. He hustled back into the living room and knelt down to Greg's head.
"This will turn you back into a human," he said, his voice shaking with uncertainty. Greg perked up at the news and allowed Mark to pour it into his mouth. He struggled to swallow it with his unfamiliar mouth, but he managed it. Mark replaced the vial into the box. Greg was trembling even more now, with both shock and anticipation. He didn't have to wait long. Soon after, Greg's hooves cracked away and quickly reformed into stiff fingers that he flexed and stretched. His arms thickened with human muscle, and what looked to be a glob of fat flowed from Greg's overfilled belly and extended through his restored arms. His legs followed suit, returning to human form and immediately getting its share of fat. His belly gurgled and reshaped, changing from a solid, round mass into a strange, complicated shape. His chest dipped down and up simultaneously, and as his human nipples were restored, it became clear that the sagging pockets of fat were his new breasts. His belly stretched and shifted, wrapping around his waist in lovehandles and filling in the space just below his breasts. His butt largely stayed as it was, but Mark noticed it shift and swell slightly as it became more human. The tail had vanished when he wasn't looking.
Mark had been so focused on his body that he hadn't noticed that Greg's head had reformed closer to his human head, but fattened. The hair on his scalp had been restored, but it stayed short, as if he had just gotten it buzzed off. Greg nervously stood to his feet. His humanity was restored, but he was still noticeably fat. He coughed a very human cough and spoke.
"Wh- I'm..." he stammered dumbly.
"I, uh, added several doses of Pig all at once, which is why you got so fat," Mark said quietly. "I guess one dose of Man doesn't cancel out several doses of Pig. Here, take another dose. You should get closer to where you were with each one."
Greg looked at the vial distrustfully but took it and downed it like a shot. He returned it to Mark, and his muscles spasmed the same way they had for Mark. Mark watched, unnerved. It was a little weird seeing it from the outside. Greg's muscles bulged and thickened with each flex. His strong muscles showed through the layer of fat on his arms, and his belly shifted as massive muscles were built underneath it. His breasts bulged out even more, pushed forward by his new, powerful pecs. Greg grew taller, and the muscles kept up, staying proportionately strong and thick with the height.
Mark was uncomfortably aware that Greg had exactly the same amount of fat as before, it was just slightly stretched out over a taller skeleton. His round jaw squared into a manly jut that was quickly carpeted over in a thick, dark blonde beard. His whole body was quickly covered in the stuff, spreading from the small patch on his chest across his torso and down his jiggling belly. His scalp hair had also lengthened a short bit, but his thick, bushy beard was much longer. Greg looked up (or rather, eye-to-eye) with Mark, who shifted uncomfortably from foot to foot.
"I guess... fat isn't unmanly," he said softly. Greg glared at Mark, bewildered. Mark turned from his gaze back to the box of vials.
"You better fix me, man," he said, his voice rumbling pleasantly but threateningly behind Mark. Mark tapped the vials as he looked.
"I will!" he said, after a pause. "I just... need to find the right vial... umm..."
"What?" Greg demanded.
"I, uh, there aren't any... uh, obvious vials for making someone thinner."
"What, you mean this is permanent?!" Greg yelled, his deep voice booming.
"No!" Mark said quickly. "I mean... yes, but there's gotta be a vial, or a combination of vials to make someone thinner. Here, help me look."