Billy's dad was frozen in shock as his son came around the corner. Billy had stripped off his clothes in the bathroom due to his increase in size. His body was quickly maturing from kid to pig, brown hairs were pushing out across his body, face protruding with a upturned nose and ears large and pointy. His body with thickening quickly as feet became hooves and hands changed slightly. He moaned as his curly tail pushed out and his childish penis was overtaken by a thick sheath, tiny balls quadrupling in size as his penis grew in the sheath becoming corkscrew like in shape.
And as quick as it had started Billy's changes stopped, leaving him part pig part man, a child thrust into a newly matured body.