Mars Hotel was a building near the studios where the album was recorded. When held upside down in front of a mirror, the illegible lettering on the front of the album cover appears to say "Ugly Rumors", apparently a play on the phrase "ugly roomers", which is a reference to the denizens of the actual Mars Hotel.
Born in Detroit, Stanley Miller became known as "Mouse" after illustrating countless notebooks with his signature rodent sketch. Miller found an outlet for his creativity in pin-striping cars and airbrushing hot rod designs on posters and T-shirts. Mouse migrated to San Francisco in 1964, where he first met the artists associated with Family Dog, the organization producing dance concerts at the Avalon Ballroom. With collaborator Alton Kelley, Mouse experimented broadly with composition, lettering and imagery: Kelley came up with the ideas and Mouse executed the designs. Mouse and Kelley helped to establish the psychedelic style of expression under the name Mouse Studios.