Aliens have been a popular subject in both graffiti art and pop art. In graffiti art, aliens are often depicted as otherworldly creatures that have landed on Earth and are exploring the urban landscape. They are often portrayed as mysterious and powerful, with glowing eyes and strange, alien features. In pop art, aliens are often used as a symbol of the unknown and the futuristic. Pop artists like Andy Warhol and Keith Haring have incorporated aliens into their work, using them as a way to comment on popular culture and the changing world around us. One famous example of aliens in pop art is the album cover for Pink Floyd's "Dark Side of the Moon." The cover features a triangular prism with a rainbow-colored beam of light passing through it, and a small, stylized image of an alien in the lower right corner. The image of the alien represents the unknown and the mysteries of the universe, which is a common theme in Pink Floyd's music. Another example is the work of artist Shepard Fairey, who is known for his street art and graphic design. Fairey has created several works featuring aliens, including a mural in Los Angeles that depicts an alien holding a boombox, a nod to the city's hip-hop culture. Aliens in graffiti art and pop art represent the unknown and the mysteries of the universe. They are often used as a way to comment on society and the changing world around us, and to explore the limits of our imagination.