When a small island community becomes overrun with creeping, blobbish, tentacled monsters that liquefy and digest the bones from living creatures, the community struggles to fight back.
| Actor | Role |
|---|---|
 Peter CushingDr. Brian Stanley | Dr. Brian Stanley |
 Edward JuddDr. David West | Dr. David West |
 Carole GrayToni Merrill | Toni Merrill |
 Eddie ByrneDr. Reginald Landers | Dr. Reginald Landers |
 Sam KyddConstable John Harris | Constable John Harris |
 Niall MacGinnisMr. Roger Campbell | Mr. Roger Campbell |
| JJames CaffreyPeter Argyle | Peter Argyle |
 Liam GaffneyIan Bellows | Ian Bellows |
| KKeith BellHalsey | Halsey |
 Margaret LaceyOld Woman | Old Woman |
 Peter Forbes-RobertsonDr. Lawrence Phillips | Dr. Lawrence Phillips |
 Shay GormanMorton | Morton |
| RRichard BidlakeCarson | Carson |
| EEdward OgdenHelicopter Pilot | Helicopter Pilot |
| JJoyce HemsonMrs. Bellows | Mrs. Bellows |
| RRoger HeathcottDunley | Dunley |