Animorphaline

A serum that temporarily turns normal people into Beastmen (as seen in early Dragonball). Manufactured by a company called Magical Pharmaceuticals, knockoffs of it were sold by the Red Ribbon Army to fund their operations. It led to a fad where, for some years, there were tons of animal-looking humanoids wandering Japan, but eventually the fad died out and most people returned to normal (unless they overdosed). Capsule Corporation manufactures an antidote for people thus afflicted.

Some gangs use injections of this serum to transform their lackeys into beasts to give them extra strength or combat capabilities.