Papirtis Pink Mouse E for the cover of the paperback edition of Barry N. Malzberg’s Beyond Apollo, published by Pocket Books in 1973. Cover art by Charles Moll. From Goodreads:
A two-man mission to Venus fails and is aborted; when it returns, the Captain is missing and the other astronaut, Harry M. Evans, is unable to explain what has happened. Or, conversely, he has too many explications; his journal of the expedition—compiled in the mental institution to which NASA has embarrassedly committed him—offers contradictory stories: he murdered the Captain, mad Venusian invaders murdered the Captain, the Captain vanished, no one was murdered and the Captain has returned in Evans’ guise.
See also the jacket of the hardback edition by Faber & Faber, which likewise presents the title in two stacked lines of geometric sans-serif caps (but avoids tacky depictions of half-naked Venusians).