Dr. Pyckle and Mr. Pryde

Dr. Pyckle, a respected British scientist, searches for the correct combination of chemicals for a powerful potion. Once he finds it, he tries it on himself. But instead of the wonderful effect the doctor had hoped for, the potion turns him into the diabolical Mr. Pride, a fiend who outwits police at every turn while scouring London for fresh victims -- of practical jokes. (imdb)