Warmed Over Monster Leftovers
Willis O'Brien and Pete Peterson began filming the special effects for 'The Black Scorpion' (1957) in a large remodeled dressing room at the Tepeac Studios in Mexico City with the aide of Ralph Hammeras, who was at the same studio filming the visual effects for 'The Giant Claw.' When the money started to run out they finished the picture in Peterson's garage in Encino, California.
To help cut the costs O'Brien dipped into his collection of critters from the 1933 classic 'King Kong.' The trapdoor spider that attacks Juanito in the scorpions' underground home is one of the original models left over from the famous deleted spider sequence, as was the giant worm with the "octopus-like arms" seen in the film.
The money problems actually got so bad that the special effects team couldn't even add the stop motion scorpions to the scenes. When the giant scorpions appear as totally black silhouettes, it is because only the black backing for those composites (to prevent "bleed-through") had been accomplished.