Home Alone is a highly quotable movie, but one of the most famous lines comes from a movie within the movie. When young Kevin McCallister is playing a prank on his Little Nero's Pizza delivery guy, or trying to get the Wet Bandits off of his property, he throws in a VHS copy of the fictional Angels with Filthy Souls. While the movie contains the now iconic, "Keep the change... ya filthy animal," line it was all done very quickly, before filming had started on Home Alone.

According to Home Alone director of photography, Angels with Filthy Souls was shot in one day, on the final day before principal photography officially started on the main movie. He says, "We had nothing to lose. We went for it." Even though it's just a movie within a movie, a lot of thought and care went into making it look authentic, while keeping with the feel of Home Alone, which meant that most of the shots were lined up to look like they were from a child's perspective. Additionally, the fictional movie had to be something that could possibly frighten a nine-year old.

The original title of Angels with Filthy Souls was "Gangster Movie." An official title wasn't decided until the crew figured out that they had a scene where Kevin McCallister has to put the VHS tape into the VCR. When it came time for a name, art director Dan Webster states that they used James Cagney's Angels with Dirty Faces to play with, which was also an influence on the noir short film that they created for Home Alone.

Director of photography Julio Macat was the one to convince director Chris Columbus to utilize the same filming techniques that they would have used in the 1940s to give Angels with Filthy Souls its authentic look. The fictional movie was shot on a sound stage in the abandoned New Trier West High School gymnasium, which is also where a lot of Home Alone was filmed. The room only consisted of two walls, and was made to look like it came straight out of the 1940s, with venetian blinds, an old school phone know as a grabaphone, as well as other things that a private investigator would have at the time.

Michael Guido was the actor who ended up playing the infamous Snakes in Angels with Filthy Souls, though he was originally cast to play the part of Johnny. Guido said that he was channeling James Cagney and had Chris Columbus laughing and urging him to ham it up some more. The result is a small part that gets the actor recognized on the street all of the time. Guido was never given the specifics about what the movie within a movie was about, so he learned later on, and is proud to be a part of holiday movie history. Home Alone will be playing from now until Christmas countless times on TV and will screen in certain theaters as well. This story was originally reported by Vanity Fair.