Return of the Monster Maker(1958)

Having escaped death (The Frankenstein Story) Doctor Frankenstein makes the decision to create a new monster. He sends Ygor and the original monster to find fresh body parts, whether from the gallows or from the living. With these new parts, the doctor creates a new monster. Unfortunately, the new monster is given a half decayed face. The new monster goes berserk, killing everybody in its path. It attempts to kill the doctor, Ygor and the original monster. The only way to stop it was for the Doctor to turn on the gas, that would kill them all.