A clumsy lab worker not really pay attention to his surroundings and distracted by his phone knocks over a vile of experimental formula. As soon it hits the floor and ahatters the gases escaped which was quickly and unknownly inhaled by the lab worker. Was the fumes entered his body the transformation started. The lab worker was writing down the report and dropped to the floor.

He started yelling his human sceams slowly becoming just hisses and other unhuman sounds.

He would soon be a Pokemon...hopefully the lab has good protection from fumes entering the vents