When he got home, he went back to the game. After booting it up, he clicked on himself, and noticed a new "Transform" option. Doing this brought up a window with an "Aware" toggle, 6 blank fields, and slider bars nest to the fields. One field had "Human" typed in, and the slider was at full. He began typing, and the human slider dropped to 50%, automatically dividing his overall species into the first and second fields.
He finished typing, and left the sliders as they were. When he pressed enter, he noticed an error message pop up. "Species conflict. Edit?" He clicked "Yes" and a new box of his sister and parents appeared. deciding that his edit should make some sense, he made his father 50% horse, and mother 50% horse as well, but only set his sister to 25% horse. After pressing enter for the second time, his focus changed to his own body.
The first thing to appear was his tail, starting as a small nub near the end of his spine, and growing about two feet long. From that spot on his back, fur started to grow, and spread over his rear, which slowly swelled with extra mass, growing firm.
Next was his feet. The program's changes were relatively harmless, so his nails hardening and foot shrinking back towards his heel only stung a little. Fur also finished growing down his legs. His stance also changed to support more digitrade movement.
His penis suddenly became very erect. It lengthened, growing a sheath and medial ring as it turned an ebony brown. it's full length being about a foot long.
Fur traveled up his torso, and he began to lose fat, making way for slightly defined muscles. His arms were similarly changed, but the nails on his hands darkened, becoming slightly hoof-like.
His head was last to change, growing out into a muzzle and becoming very equine. His hair grew into a straight mane of black hair, slightly past his shoulders. His ears tingled as they grew out, also becoming equine.
He looked back to his computer, to see his mom and dad looked similar to him as parents do, but his sister had become comparatively less changed, only having hooves, a tail, and equine ears instead of her normal human assets. Now that these changes had finished, he pondered what to do next.