Continuity mistake: Just before the giant tarantula attacks the house where heroine Mara Corday is studying, you can see several book on the library table at the big picture window. The largest book on the table keeps shifting positions in several scenes.
Continuity mistake: Lobo has a very distinct scar on his cheek in the beginning and end of the movie. However, just after Dr. Strowski has entered the house, Lobo is seen coming down the stairs, and his scar is completely gone.
Continuity mistake: Shortly after the movie starts, Cal's plane lands and they go into the lab. Cal looks through a scope at an experiment and his assistant is next to him without glasses. After the experiment flames out, they show the men again but now his assistant is wearing glasses. (00:08:50)