Snow White and the Seven Samurai is a film. The Turtles talk about renting it from the video-rental in the beginning of The Dimension X Story episode during season 4 of the 1987–1996 animated TV-series. In order to get their hands on it, they had to lie in wait outside the rental store and Raphael had to infiltrate the store before other customers could request the film.
Title-wise, it's based on the Grimm Brother's "Snow White and the Seven Dwarfs" fairytale, which became an animated Disney film released in 1937. It also shares ties with the 1954 Japanese film "Seven Samurai", directed by Akira Kurosawa.