For "Mant", the movie-within-the-movie, Joe Dante cast actors who had appeared in 1950s-era science fiction movies. These included Kevin McCarthy, Robert Cornthwaite, and William Schallert.
Lawrence Woolsey is based upon the real Hollywood showman William Castle. The character is introduced in a re-creation of Castle's famous trademark of a silhouette of him in a director's chair with his head turned in profile with his cigar. His name is a reference to Lawrence Woolner, one of the Woolner Brothers whose company, Woolner Brothers Pictures, distributed sci-fi classics like Attack of the 50 Foot Woman (1958).
Cathy Moriarty's character is named Ruth Corday. This is a tribute to Mara Corday who starred in Tarantula (1955), The Black Scorpion (1957), and The Giant Claw (1957).
In her memoir, Lisa Jakub stated that she had her first kiss while filming this movie. Her scene partner Simon Fenton apparently did not like Lisa, which made shooting the five takes of the kissing scene very awkward and uncomfortable.
For "Mant", the movie-within-the-movie, Kevin McCarthy plays a character named General Ankrum, a tribute to character actor Morris Ankrum, one of the most familiar faces in similar supporting roles in real science-fiction films of that era.
Joe Dante: [Regular Cast] Dick Miller. Director Joe Dante frequently casts Dick Miller. Dick Miller plays one of the two "protestors" who are trying to stir up interest in "MANT", the movie-within-a-movie. During the screening of "Mant", Miller can also be spotted in one of the crowd scenes with General Ankrum. He's wearing a helmet and holding up the giant bag of sugar.