Venom

A kidnapping that turns into a hostage siege and then a death trap. Venom (1981) is a British horror-thriller you can watch online on iFILM, directed by Piers Haggard and locked almost entirely inside one London townhouse.

A gang sets out to abduct the sickly young boy of a wealthy family. The scheme collapses over one freak mistake: instead of the harmless pet snake the boy ordered, a Black Mamba — among the deadliest reptiles alive — is delivered by error and slips loose somewhere in the walls. Now the kidnappers and their captives are sealed in together with an unseen killer gliding through the house, police ringing the building outside, panic boiling within. The cast pits Klaus Kinski against Oliver Reed, with Sterling Hayden and Sarah Miles.

The dread runs on two engines: a genuine fear of the snake, and the legendary off-screen loathing between Kinski and Reed, who couldn't stand each other on set. A sharp pick for fans of tense late-'70s and early-'80s genre cinema. Stream Venom (1981) online on iFILM.