When an underwater volcanic eruption tears up the sea bed off the coast of Ireland, two treasure hunters make the discovery of a lifetime when they encounter a gigantic prehistoric monster that’s been unleashed from the earth’s crust. After capturing the beast, the pair transport the creature down to London where it’s given the name of “Gorgo” and put on display to an avid public. Little do they realize that Gorgo is just an infant, and that his exponentially larger mother is about to emerge from the depths to avenge the capture of her offspring.

Bill Travers
as Joe Ryan

William Sylvester
as Sam Slade

Vincent Winter
as Sean

Christopher Rhodes
as McCartin

Joseph O'Conor
as Prof. Hendricks

Bruce Seton
as Prof. Flaherty

Martin Benson
as Dorkin

Maurice Kaufmann
as Radio Reporter

Basil Dignam
as Admiral Brooks

Barry Keegan
as Mate
CinemaSerf
Bill Travers does his best Stephen Boyd impersonation here as "Ryan", who leads a gang of scavenging sailors who survive an underwater earthquake that delivers a giant lizard into their hands (or nets). Determined to capitalise on their luck, they do a deal with "Dorkin" (Martin Benson) to exhibit t...