The Monster That Challenged the World (1957) - S30.E41

(Second episode of the night as part of Svengoolie's Halloween BOO-Nanza)

An earthquake awakens a nest of monsters lurking in the Salton Sea. These bloodthirsty sea snails are gobbling up anyone who sets foot in the water. And when the creatures move on to land in search of wider hunting grounds, they launch a reign of terror that threatens to spread across the whole country.