This movie has a good FX pedigree: Willis O’Brien, creator of the stop-motion animation effects for the original King Kong, was the special-effects supervisor. There’s an urban legend that the spider pit creatures that were cut from that film show up here. While Ray Harryhausen’s An Animated Life would claim that many of O’Brien’s models  were still in storage at RKO when this was made, many of them were pretty decayed by that point.

An earthquake happens in Mexico and a new volcano rises, along with someone who believes that a demon bull has come out of hell. If only it could be so simple. Instead, the beasts are gigantic prehistoric scorpions.

How do you kill a monstrous scorpion? You fill an arena with meat and then shoot it with a spear that’s attached to an electric cable, then spark that thing up. You have to admire that level of ingenuity.

October 1958 Playboy Playmate Mara Corday was probably used to this kind of thing by this point, having already dealt with Tarantula and The Giant Claw. I can see dealing with one giant monster, but three? Yeah. That’s being a magnet for kaiju.

An even bigger coincidence is that six of the actors in this movie — Carlos Rivas, Mario Navarro, Pascual García Peña, José Chávez, Roberto Contreras and Margarito Luna — all appear in another Willis O’Brien-animated giant monster movie, The Beast of Hollow Mountain.