Off the coast of Sicily fisherman are going about their work, casting their nets in the sea when suddenly there's the sound of something roaring out of the sky: a spacecraft which narrowly misses them, flying over their heads and into the water nearby. One boat goes over to investigate, seeing the hatch is open, and the fishermen clamber inside, accompanied by the young son Pepe (Bart Braverman) of one of them. What they find is the dead crew, although two men are still alive and they are dragged from the wreckage - but Pepe finds something else, a canister containing what looks like a large egg...
Thus special effects master Ray Harryhausen continued on the first phase of his career concentrating on what really interested him: making monsters. Inside that egg was one of his first monstrous creations, as his previous film had seen him animate the saucers of Earth vs. The Flying Saucers, but here he was able to fashion a reptilian creature very much in the mould of a path he would be following for the rest of his vocation, and in that way quite momentous for the history of silver screen monsters. Otherwise there was the air of your basic science fiction terrors from the nineteen-fifties about 20 Million Miles to Earth, making this sort of the American Quatermass Xperiment.
So it was basically your capture the space beast before it can do any more damage business on offer here, except that damage was precisely what the audience wanted to see, and they were rewarded with a sizeable amount of destruction. Of course, the budget wouldn't stretch to the full eighty minutes of running time, so there were diversions as the surviving crewmember of that mission to Venus (where they had found the egg) gets to romance the doctor who treats him, that was Colonel Calder (William Hopper) and Marisa Leonardo (Joan Taylor), but their scenes together are the very essence of perfunctory. It was clear everyone was here for that monster.
Which was named the Ymir unofficially, as nobody calls it that in the film, but that's what has stuck with it ever since as Harryhausen named it that when he was designing it. Once it hatches from the egg, it begins to grow thanks to some casually mentioned scientific mumbo-jumbo about it being affected by the Earth's atmosphere, so before long it is almost the size of a person, which proves tricky to keep caged which becomes apparent to the Professor (Frank Puglia) who was taking it to Rome for study on the back of his truck. Soon the creature has broken free, leaving it to begin its campaign of terror across the Italian nation, or at least maul a dog when it finds some sackfuls of sulphur at a local farmhouse.
It eats sulphur on Venus, you see, so this is what sustains it in one of those offbeat logic moments you would often find in sci-fi of this vintage. Needless to say, the Ymir is superbly animated, with Harryhausen already displaying a mastery of his craft, but also a surprisingly bloodthirsty side as it was here the violence his creations partook in truly got going. Sure, those flying saucers, giant octopus and rampant dinosaur had smashed up a few buildings and whatnot, but here you got to see a space alien mangle a hapless farmer, crush soldiers under rocks, and most famously beat an elephant to death with its bare hands (claws?) in some bravura sequences, just the kind of thrills which the audiences of the days were delighted to see, and make this endure to this day. If there was anything missing, it was the pathos of Harryhausen's beloved King Kong, as while the Ymir gets his own would-be iconic showdown at the Colisseum, you can't honestly say you shed a tear for him, but the spectacle went some way to making up for it. Music by Mischa Bakaleinikoff.