That version had been produced by David L. Wolper in cooperation with the Smithsonian Institution and was narrated by Rod Serling.
[3] The Mysterious Monsters was one of the first theatrical releases produced by Sunn Classic Pictures.
The film investigated not only the possibility of Bigfoot's existence but also of the Loch Ness Monster and the Yeti (the Abominable Snowman).
Famed Bigfoot hunter Peter Byrne was also featured and gave insights on the hunt.
In discussing the Loch Ness Monster, the film showed a 1934 photograph that was said to be of the creature.