"Sell the sizzle, not the steak" was the motto of post-war men's magazines. The contents of the mags were merely an afterthought - it was the cover that sold them. During their peak in the mid-fifties, these sleazy illustrations were stacked right alongside The Saturday Evening Post and Popular Mechanics.
I could literally devote the next year to writing about the impossibly gratuitous cover art and lurid headlines (ex. "Nude Lust Slaves of Hitler's Russian Monster") and only scratch the surface of the post-war male pathos. Sigmund Freud would have a field day with these magazines!
So, instead of looking at the entire genre, let's just focus on their tendency to have covers depicting women being ravaged and mutilated by wild animals.
These covers depict women being attacked by basically any animal you can think of: elephants, monkeys, cheetahs, lions, panthers, boa constrictors, crabs, scorpions, gorillas, alligators, snapping turtles, ants, vultures, boars, etc., etc. You name the species, and I guarantee there's a cover of it torturing and eating a scantily clad woman.
Okay, I haven't seen a koala attack yet, but that's not to say it doesn't exist.
There's such an encyclopedia of wild animals killing ladies that they could almost serve as a learning tool for species identification... that is, if they weren't so unbelievably brutal. Which brings me to my main thought - what is it about a cover depicting a half-naked woman being gored by a wild boar that had hundreds of thousands of men buying it?
I think it had a lot to do with WWII and the atrocities and inhumanities that these men faced on a daily basis. It couldn't have been an easy adjustment going from a world of omnipresent violence to humdrum suburbia and the daily monotony of the factory.
Similar surges in ultra-violent media occurred after WWI in pulp magazines and after Vietnam in exploitation films. Of course, there's other factors at work here: the damsel in distress motif has been in effect since the dawn of time, as has the "man vs. wild" theme. Sprinkle in a liberal dose of T&A and it's not hard at all to see why they couldn't keep these magazines on the shelf!