A giant octopus, whose feeding habits have been affected by radiation from H-Bomb tests, rises from the Mindanao Deep to terrorize the California Coast.
| Actor | Role |
|---|---|
 Kenneth TobeyCmdr. Pete Mathews | Cmdr. Pete Mathews |
 Faith DomergueProf. Lesley Joyce | Prof. Lesley Joyce |
 Donald CurtisDr. John Carter | Dr. John Carter |
| CChuck GriffithsLt. Griff, USN | Lt. Griff, USN |
 Ian KeithAdm. Burns | Adm. Burns |
| DDean Maddox Jr.Adm. Norman | Adm. Norman |
 Harry LauterDeputy Bill Nash | Deputy Bill Nash |
| RRichard W. PetersonCapt. Stacy | Capt. Stacy |