A bad formula double feature!
1st Dr. Jekyll and Mr. Hyde (1931)
Dr. Jekyll faces horrible consequences when he lets his dark side run wild with a potion that transforms him into the animalistic Mr. Hyde.
My favorite film version! Starring Fredric March.

2nd. The Manster ( 1959)
An American reporter in Japan is given a mysterious injection by a scientist, who turns him into a two-headed monster.

w/ TRIVIA & PRIZES