Kind of an Italian version of those great old Kharis the Mummy movies, this is pretty dull for long stretches, even with the bombastic narration telling us what's going on. On the other hand, it does have a neat, actual, no-nonsense Monster and we get to see it in action a couple of times (rather than just for a few minutes at the very end). Instead of a dried-out bandaged Egyptian, here we're dealing with the re-animated corpse of an ancient Etruscan gladiator Quintillus. He keeps coming back to sort-of-life to chase after his reincarnated girlfriend.
But because he was killed in the eruption of Pompeii, Quintillus is caked in a shell of crusty volcanic ash that somehow is flexible enough to let him move but still hard as rock when people shoot at him. When Quintillus smacks people with those stone mitts, they go down! (A career in boxing would be a cinch.) In his mind, he's reliving the ancient disaster and desperately trying to find his sweetie so he can carry her into the ocean to escape the eruption. This gives him a motive we can sympathize with; the best monsters always have their own point of view that's not just sheer evil for its own sake. The modern woman he's fixated on understandably objects to be carried around like that, scientists and police get caught up in the agita and the results are enjoyable in a low-key, 1950s drive-in way. One distinctive note is that no one comes up with a way to stop Quintillus, no one says, "That's it! We need to freeze him!" or "Wait a minute, he's vulnerable to bright light!" Nope, the Faceless Man just walks over everyone and actually makes it to the sea with the girl in his arms... of course, then he finds out how mud is made.
Edward L Cahn directed this and a passel of other great cheesy drive-in flicks, including IT! THE TERROR FROM BEYOND SPACE, INVASION OF THE SAUCERMEN, CREATURE WITH THE ATOM BRAIN and INVISIBLE INVADERS. He knew what we wanted to see through the windshield. (Well, nudity to be honest but he couldn't deliver that.)