His cameo appearance became the first genre film appearance for "Famous Monsters of Filmland" publisher Forrest J. Ackerman. This led to another facet of his career in which he would make numerous cameo appearances, and even do bit parts, in films for more than 40 years.
Peter Strudwick personally contacted Ib Melchior about possibly playing the role of a monster in this film. After visiting Melchior at his house, Melchior wrote the part of The Mutant for Strudwick to specifically portray.
When it is revealed the future humans are travelling to Alpha CentaurI, one of the scientists responds "twenty-five thousand-billion miles!" This is actually quite accurate: Alpha Centauri is about 4.37 light-years, a little over 25 trillion miles, from our solar system.