USA Today - 06/28/2002
"...One of Ray Harryhausen's most memorable creatures and a grand Rome Colosseum finale make this a boomer favorite that still holds up..."
The first space flight to Venus returns to Earth carrying a specimen of Venusian life called the Ymir. When the ship crashes into the sea upon its re-entry into Earth's atmosphere, the small, reptilian creature escapes, growing to an enormous size, eventually terrorizing the city of Rome. The always beautiful and impressive creature animations of the great Ray Harryhausen elevate the film above the level of ordinary 1950's monster sci-fi. The Ymir is one of the best-known creations in his long, distinguished career.
A space mission returning from Venus crashes into the sea near Sicily. The only surviving astronaut heads a mission to capture the cute reptilian creature that accompanied the crew to earth. Initially, scientists attempt to study the quickly growing organism but the alien life won't submit to being a laboratory specimen. Before long, the monster will gain full strength, escape the lab and destroy Rome.