Un chien andalou is a 1929 silent surrealist short film directed by Luis Buñuel and co-written with artist Salvador Dalí. It is known for its shocking imagery and dream-like sequences that defy conventional narrative structures, making it a landmark in the realm of experimental and avant-garde film. The film's purpose is to challenge traditional storytelling and provoke emotional responses, emphasizing the subconscious mind and irrationality through its startling visual metaphors.