Writer-director Larry Cohen, according to interviews, once looked at the Chrysler Building and said: "That'd be the coolest place to have a nest." This single thought was the idea which began the creation of this movie.

They couldn't fit the giant egg and nest into the Chrysler Building's attic, so they shot these scenes in an old, abandoned police building. When they were finished shooting the crew removed everything except the nest. "Close to a year later there was an article on the front page of the New York Times," Larry Cohen said detailing a flurry of activity from anthropologists flying into town to examine a mysterious nest found in the old, abandoned police building. "I wasn't about to say anything about it, I didn't know what the liability might be."

The building in the opening scene of the movie is the Empire State Building. In this scene, a window cleaner loses his head to the monster. His name is William Pilch, and was the actual window cleaner for the Empire State Building at the time of the movie's filming.

The film poster's glossy monster illustration was painted by science fiction/fantasy artist Boris Vallejo.

Bong Joon-ho was influenced by this film while making The Host. Bong was excited by the idea of mixing humor with a monster picture.

Larry Cohen: The photographer who snaps a pic of the flayed corpse in the hotel room.