Phantom Creeps (1939)

Dr. Alex Zorka (Bela Lugosi), eccentric scientist, carries on mysterious experiments in his secret laboratory with the aid of Monk (Jack C. Smith), an ex-convict. Zorka has invented many strange and powerful weapons of warfare, including a devisualizer belt which allows him to operate without being seen, and a terrifying mechanical robot eight feet tall. He also possesses a deadly meteorite fragment from which he extracts a strange element which can induce suspended animation in an entire army.