Almost all the cover art for Sci Fi pulp fiction was good. It often was very good even in the lower grade publications. But a few artists stand out. You see their work and you know it before you read the signature. This is the case for a fellow who signed himself simply as EMSH.
Ed Emshwiller had a long career as an illustrator, later he was an accomplished film maker. Perhaps the quality of his art reflects his training at the Ecole des-Beaux Arts in Paris in the post war years. Here are a few of his works as found in my little trove of garage sale bargains...
Emshwiller would often put science fiction writers and others into his pictures. I suspect the alien artist - kitted out as he is in a French get up - is a self portrait. Note the letteres EMSH carved into the marble behind the implausibly garbed Space Babe.
One has to assume that Gene Roddenberry and the writers of Star Trek all read this stuff. You could not come up with a much better portrait of a "Proto-Kirk".
One of Emshwiller's neighbors in the suburban community of Levittown New York was a kid named Bill Griffith. This friendship influenced Griffith to go on and create the comic strip Zippy the Pinhead. Griffith's parents were occasional models for the cover art, and in 1957 a 16 year old Bill Griffith himself was depicted, gleefully ignoring an angry Kruschevesque figure (his father as it happens) who is ordering him to return a stolen rocket ship!
Probably the most famous EMSH covers were a recurring series that appeared in Decembers from the early 1950s until the just after 1960. They all feature a Santa Claus with four arms. The joke seems never to have been explained, presumably the extra appendiges were useful for delivering the daunting number of toys that good little girls and boys had coming to them on Christmas Eve!
Because the Internet exists to show us this sort of thing, here is a gallery of EMSH four armed Santa covers from 1951 to 1960. Squid Santa and RoboSanta, no extra charge.