In the 1960’s, sending space probes to Mars was a crapshoot; both the US and USSR lost very expensive spacecraft. This was due to one simple fact: spaceflight is hard. But in 1965, JPL engineer (John Casani) jokingly told a reporter that the problem was the Great Galactic Ghoul, a Mars-based monster that kept eating spacecraft. A few years later when Mariner 7 seemingly disappeared, a JPL artist (G. W. Burton) painted the Ghoul chomping down on the probe.
I’ve posted the full-rez scan (from an 8X10 B&W glossy) to the 2017-08 APR Extras Dropbox folder for APR Patrons ($4 and up level).