Frantically, Matt scoured the screen for a cancel button now that he understood the option he had accidentally clicked on. Unfortunately, he had to drop the mouse as a full-body wave of itching washed over him and he started trying to scratch every inch of himself within reach. Finally, the itching died down a little, and he gasped as he glanced down at his arms. They were now covered in white fur mottled with black spots. He stared at his furry hands and arms, mesmerized. Pulling his shirt up and off, he marveled at the black and white coat that had fully overtaken his chest and belly.
An odd swelling feeling started in his ears, then a confusing muddle of sensations as they totally reshaped. By the time his gaze reached his bedroom mirror, they had fully transformed into long, broad flaps hanging over the sides of his head. He reached up with his furry hands and gently tugged them in a kind of stupor.
"Uh oh," he said when swelling feeling started in his lower back. He felt new skin and hair brushing against the fabric of his pants. He pulled them down just in time to see his long, slender white tail stretch out a few more inches and stop growing. He was about to reach down and grab it, but his hands were gripped by pain as claws and pads sprouted out from them and they became paws. His legs and feet changed, so that he wobbled and finally fell onto all fours.
Remembering the voice activation, he tried to shout out, "Computer! Stop! Cancel! Undo!" but it only came out as a series of yips and barks. He felt his tail tuck itself between his hind legs as he realized he could no longer talk.
As his face pushed out into a muzzle, though, an unexpected calm feeling started to wind itself into his consciousness. Matt's mind filled with images of fun walks with his dad, exciting rounds of fetch in the yard, and his favorite dog food getting poured into his bowel. He knew that these these "memories" had never actually happened to him, of course, and that it was just the Chronivac's reality changes finally affecting his mind. Still, he did find himself starting to wonder why he had been so upset when the device started turning him into a dog. After all, given his own vague request and the AI's limited understanding of human figures of speech, it was only logical that the computer should immediately transform him into "man's best friend."
He was distracted from his philosophizing by the welcome sound of a familiar voice calling his name from the living room.