"What was your friend's name again?" asked the witch. "Damon," said Chris, immediately throwing him under the bus. John punched him in the shoulder.
"Hm. I'll deal with him later. In the meantime, let's get you two ready. Your lives of crime are over. You're going to live here and be under my complete control from now on. If you learn your place, you'll have happy lives here."
Her hands glowed and cool green flames painlessly burned off Chris and John's clothes leaving them naked. It also left behind a new garment on their necks that they weren't wearing before. Leather bands around their necks with name tags on them. Their mouths dropped open in shock but then something strange happened. They began to sniff the air.
"Hey, man, does everything smell--stronger in here to you?" asked Chris. His nose was getting wetter, turning black. John's was turning pink.
"Fuck, let's not worry about that right now," John retorted, "here, help me get this damn pet collar off. How did it even get on me? And put your junk away, ain't nobody wanna see that shit."
But before Chris could do either, they both doubled over as the magical heat-less fire consumed them again, this time going up into their mouth and nostrils, settling down inside them. An alien energy seemed to fill them up inside, before sinking down lower and pushing its way out from their asses. Or rather right above their asses.
The nude thieves dropped to their hands and knees and groaned, feeling their tailbones swelling. Splitting up in weird, flexible new segments. Getting heavier on their hips and backs. When it finally subsided, they stood back up, but when they saw each other they also saw lengths of bony skin hanging down behind them almost to the floor.
"What the hell is sticking out of you, Chris?"
"What is sticking out of YOU?!"
Hearing each other ask that, they each immediately looked back behind themselves, and as they did, the massive growths raised up in front of their faces, giving them an awareness of strange new muscles they had never flexed backed there. These foreign limbs were starting to move--starting to get unruly. John's was waving fluidly and twitching daintily at the very tip, whereas Chris's was crudely swinging like a pool noodle. The two thieves wasted no time reaching for what had grown out of them, desperate to stop the moving and quell the odd sensations in their spines. The things were quick and took some effort to catch, though! But they did, and felt themselves get grabbed as though their backbones had a handle. John, wanting his gone, tried to yank his off, and---"AAAAH!!"---learned the hard way not to tug when one's own spine is in one's hands.
The witch was laughing. "How adorable! You two don't even recognize your own tails, yet. Don't worry. You'll get used to them soon enough." The appendages in question began to feel fuzzy against their owners' palms. Hair was growing on them. No, not just hair. Fur. Black fur. Chris gasped and yanked his hand away. The furry thing curled down between his thighs in an expression he thought he recognized. Looking down knew where he'd seen a tail like this before.
"D-d-d-dog?" he stammered. "Good boy!" praised the witch. His swollen ears perked up to her voice. Swollen ears?! He reached up and felt a pair of wide, thin flaps still growing, starting to bend under their own weight. They finally just flopped over entirely, to dangle beside his head. The sounds around him were getting crisper, echoing louder. The fur was spreading down his legs and up his back. Chris saw John's ears, instead, were pointy triangles. Long whiskers were sprouting from John's cheeks. John was growing more black fur, too, and not just on the tail that was longer and more flexible than Chris's own. "You're turning into a cat, John!"
But John couldn't admit it. "No. N-no, this, this CAN'T be real!"
But it was real. The fur was almost to their feet and was wrapping around closer and closer to their groins. Their ears twitched, learning to take in sounds that had been off limits to their human selves. The uncomfortable magic force that had sprouted their tails welled up inside them again, preparing to reshape their bodies even more.