The Devil Bat

After brilliant scientist Dr. Paul Carruthers (Bela Lugosi) develops an ingenious product for a cosmetics company, he is cheated out of his fair share of the profits by his greedy partners. Hell bent for revenge, he decides to turn his laboratory of science into one of doom as he creates a giant race of bats that turn into ripping and shredding beasts of fury, designed to attack anyone wearing the very product he invented.