"The Forms of Things Unknown" is an episode of the original The Outer Limits television show. It first aired on 4 May 1964, and was the final episode of the first season. It was filmed in a dual format as both a regular episode of "The Outer Limits" and as a pilot episode for a possible series called "The Unknown". The opening and closing narration listed here are only in "The Unknown" version and not in the broadcast The Outer Limits episode. There are plot differences between the two versions as well.