An American rocket returning from the first manned space flight to Venus crashes into the sea near Sicily. One of the crew members is killed, but Colonel Bob Calder (William Hopper) survives with only minor injuries.
Also surviving the crash is a gelatinous mass containing some sort of embryo, which is found by the young, cowboy-obsessed Pepe (Bart Bradley). The creature inside the sac eventually emerges and is, at first, a tiny reptilian creature that stands upright on two legs and fascinates biologist Dr Leonardo (Frank Puglia) and his trainee doctor daughter Marisa (Joan Taylor).
But the creature grows at an alarming rate and is soon on the loose in the Italian countryside and making its way towards Rome. The snake-tailed giant Ymir monster is also one of animation master Ray Harryhausen’s finest creations (and his own personal favourite) with a well-defined personality and manages to evoke sympathy for its bewildered plight.
It is pursued and harassed by an American military team who want to capture it alive but are quite happy to electrocute it into unconsciousness, and by the Italian authorities who just want to kill it before it can reach Rome and cause even more damage.
The Ymir’s brutal fight with an elephant and the Roman locations – especially the climactic Colosseum battle – add unique touches to this minor classic.
The decision to set the action in Italy was made, apparently, because Harryhausen fancied a holiday in Rome.
Colonel Bob Calder
William Hopper
Marisa
Joan Taylor
Dr Leonardo
Frank Puglia
Dr Judson Uhl
John Zaremba
General AD McIntosh
Thomas Browne Henry
Police commissioner
Tito Vuolo
Signore Contino
Jan Arvan
Sharman
Arthur Space
Pepe
Bart Bradley
Director
Nathan Juran