Goofs

The close-ups of Konga's feet on the streets of London are out of scale with how he appears in full shots.

When Konga arrives at the Great Clock of Westminster, the time shows about 11:38. In about five minutes, movie time, Big Ben strikes Midnight as Konga lies dead by the side of Dr. Decker.

Margaret, Dr. Decker's assistant, is clearly shown as a prop doll in the wide shots in which Konga grabs her. She is only shown as such when the camera is not near her face.

The second time Konga grows, this time into a giant, his feet are cut off by the traveling matte.

The prop dolls carried by Konga were made at a different scale to the model backgrounds and buildings. This is especially noticeable during the lab fire: the woman would only be the same height as the lab bench.

Dr. Decker is wearing a black suit in close-up matte shots of him being carried by Konga in his hand, but in long shots his prop doll is clearly dressed in a navy blue suit.

When Konga first picks up Margaret after she injects him with the serum to make him grow into a giant, you can see her head in front of the green screen. No background was filled in.

Real Venus fly traps seize their prey when hairs on the inside of their leaves are touched, and dissolve their prey over a long time. The huge mutated plants in this film, however, are shown almost begging for meaty treats like animals and gulp as if swallowing their food.

When Dr. Decker is showing his movies of his adventures in Africa, many of the stock sequences come from footage taken of inhabitants of Papua New Guinea or nearby islands, not Africa.

There is no explanation given at all as to what actually happened to Sandra Banks (Claire Gordon) toward the end of the film. She is last seen being distressed after accidentally getting her lower arm trapped in one of the huge mutated Venus fly traps, but then she disappears from the film completely after that! Surely it is ridiculous to suggest that she was eaten alive and whole in this manner. All she would have suffered at best was a small wound on her lower arm, and this resolution should have been seen and shown as such.

A chimpanzee cannot physically change into a gorilla. These African great apes are actually four entirely different species (two species of chimpanzees and two species of gorillas).