Jack was so tickled by what he was planning he'd never given a thought to anyone else being in the house. The computer was blinking the ready sign as he was taking off his clothes.
Looking to the plexiglass cubical the emmitter was already spitting small rays of green and blue. He felt ready and had the plan to be something more worthy to become a farm's stud and prime sire. Jack had checked the phone book and was remembering the address of the Monticello Mule Farm.
All seemed set as he looked at the clock, it was almost to the stroke of midnight.
Naked as a jaybird but still sporting the groin of a male Jack named Jack he poked the start key and stepped into the cubical.
The door closed and he heard a distinctive snap as it locked tight with a magnetic lock. At first he was alarmed by this but thought the computer would release the lock when the transmutation was complete.
"Jack, Jack, its time even a good student get to bed!" said Jack's Mom as she walked into the room.
Jack turned to stand as he was looking in horror at his mother and him being somewhat mutated and totally naked.
Quickly he turned his back to her as she began to exclaim, "Jack, what on earth are you doing, what is this thing, Jack, Jack?"
One by one the emmitter ray began to jet out the electrons as Jack felt embarressment and horror over being seen as a Jack named Jack.
Almost instantly as the green rays touched his outer body the colour of his skin changed to a deep leathery black hide. Hairs too spouted making some as dark brown to black spots, while the rest of his hair was pure white.
Mom, by this time was wide eyed and speechless seeing her young son changing before her eyes.
Those true donkey ears grew up again giving a tickling sensation which made Jack laugh. As his tail erupted from above a broadening ass end his butt hole bloomed large and black looking like the perfect rear of a fine big jack.
He turned to give an evil look toward his mother as she was spewing out a scent any Jack would love to sniff. Nervous was she as Mom pressed her face to the clear plexiglass wall and mouthed her horrid thoughts.
A wiggle of one leg had the emmitter arranging Jack's leg muscles and bone structure. His human leg and foot seemed to melt into the common shape and form of a hind leg of one sturdy mature male Donkey. Even when the toes merged to make his solid one toed' hoof he looked at his mom feeling pride.
"Jack, J...a...c...kkkkkkkk!" said Mom as she slid down the outside of the plexiglass wall. Her eyes closed and Jack saw her body become limp, she'd fainted!
Forelegs and hoofs now solid and stout of muscle and bone Jack turned in the cubical his enlarged Donkey self filling the space available. Yet the computer worked on as the emmitter's green rays were turning blue and then all blue.
From the emmitter above his head came a voice of some man.
"Congratulations, you have just been cured from all your physical abnormalities. As a bonus to your continued good health this program assures that these changes are both as complete as this machine can make them, and what's most important, this is all permanent!" said the voice as Jack wondered if he'd done the right thing.
Click, went the magnetic lock and the thin glass door swung open as both the emmitter and the computer itself shut down.
Jack slowly stepped out of the hot cubical and stood lip nibbling at his fainted mother. He wanted to say he was sorry, but he really wasn't as his Donkey Jack self was so very, very horny.