Several shots are from Universal's The Invisible Man Returns: the scenes where the guinea pig is turned Invisible (reversed footage), the harness of the invisible guinea pig moving around its cage and the scene where the Invisible Man is unpacking a suitcase of clothes left outside in the woods.
The last names of Bud Abbott and Lou Costello's characters, Bud Alexander and Lou Francis, are actually their real middle names.
The picture in Dr. Gray's laboratory of Griffin, the inventor of the invisibility serum, is a photo of Claude Rains, who played the title role in The Invisible Man.
This was originally intended to be a straight film in the Invisible Man series. After the huge grosses from Bud Abbott Lou Costello Meet Frankenstein, the script was rewritten to make it another thrill comedy with Bud Abbott and Lou Costello. As it happened, Abbott and Costello met an invisible man in the earlier film, too, but it was a different character.