The edition of Oh Boy! dates from 1949 and shows the young Monkhouse's superhero creation Tornado battling to save a half-naked woman from a race of slimy-headed aliens called the Kharucha who bear a passing resemblance to giant penises.
It features in a sexually explicit section of a British Library show entitled Comics Unmasked: Art and Anarchy in the UK, and comes complete with a parental guidance warning for under-16s.
Monkhouse, who was probably best known as a game show host and stand-up comic, wrote and drew hundreds of comic strips and is said to have contributed work to the Beano while still at school.
Co-curator Paul Gravett said: "One thing that people will find surprising are some of the famous names that have made comics. We've got people like Enid Blyton, Anita Roddick, the founder of The Body Shop and even Grayson Perry has produced them.
"Most surprisingly to most people would be the comic from Bob Monkhouse. He was only a teenager at the time, and he produced this slightly bizarre superhero called Tornado who fights some rather disturbing looking aliens, let's leave it at that!
"They are certainly the work of a highly hormonally challenged teenager. They are very funny, and they are probably a different side to Bob Monkhouse's wonderful career."
The exhibition, at the central London building, also includes work from notable titles such as Watchmen, V For Vendetta and Batman and Robin among an array of items.
Artwork from the occult figure Aleister Crowley and editions of the underground counter-culture publication Oz will also be on display until mid-August.
A previously unheard recording of the early 1970s "Oz trial", in which the magazine was successfully prosecuted for obscenity, also features in the exhibition.
The show runs until August 19.