An earthquake awakens long-dormant giant, prehistoric molluscs in a cave beneath the Salton Sea. These critters take a liking to feeding on humans, which they do by sucking out all the blood and water from their victims. Once the authorities realise what they are up against, they attempt to wipe out the creatures before any of them can migrate up the All-American Canal, spread through the Imperial Valley, and then threaten the world.

It is then theorised that some of the monsters may have found their way to one of many small lakes dotted between the Salton Sea and the canal… so our heroes must locate the precise lake in order to destroy them before the creatures can expand in numbers.

THE MONSTER THAT CHALLENGED THE WORLD is efficiently directed by Arnold Laven (who usually directed for TV) and was written by Pat (THE FLAME BARRIER) Fielder, based on a story by David (THE TIME MACHINE) Duncan.

This is a solid entry in the 50s B movie sci-fi creature feature genre, showcasing one of the better film monsters of the period. These mollusc-things have a long, centipede-like upper body, which emerges from a huge snail shell.

The plot is decent enough, but there really should have been more scenes featuring the monster on-screen, because this critter is a beauty!

Tim Holt, who was really good in THE TREASURE OF SIERRA MADRE, is unfortunately charisma-free here as the no-nonsense Lt. Cmdr. John ‘Twill’ Twillinger, Audrey Dalton is adequate as love interest Gail MacKenzie, Hans Conried, known for his voice work in cartoons, does better work as Dr. Jess Rogers, though the standout performance for me comes from Milton Parsons, who plays a dour, morbid shop owner in a couple of scenes.

The briefly-seen, withered, husk-like faces of several victims stick in the mind and provide relatively grisly imagery for a film of this period. The best moment involving one of these sucked-out faces comes when two Navy divers are attacked by an awakened monster mollusc, which grabs one of them to suck out his juices… and we get to see his emaciated face staring through his diving mask.

The satisfying finale has Holt taking on a final monster, which has hatched from an egg kept in a vat in the military base’s lab. Making the most of the full-size creature model, the filmmakers get it to smash a door, knock over equipment and ram its head through the lab ceiling. The stoic hero fights the beast with a fire extinguisher and a broken steam pipe, but I’m sure every viewer who has ever watched this confrontation has yelled at the screen, telling him to grab the big fire axe that is teasingly in view for most of this sequence! Armed Navy personnel finally arrive, however, blast the monster with their rifles, and the fine-lookin’ mollusc monster crashes to the floor.

Here’s a bit more information about the creation of the creature:

Augie Lohman, who had worked previously on films like MOBY DICK (1956), LOST CONTINENT (1951) and THE MAZE (1953), was responsible for the mechanical mock-up of the monster, which could move both laterally and vertically through the use of hydraulic and electric machinery. The monstrous model took three-to-five men to work the rheostats and other controls that moved the monster either up or down, frontwards or backwards, or provided it with a rolling forward movement.

Some publicity shots…

Here are some monster-tastic posters…

Here’s the box art for a super 8 home movie reel…

Okay, one more look at the stupendous creature…

I lied! Here’s yet another look at the monster mollusc…