In 1962, Topps released a controversial trading card series that depicted the gruesome annihilation of "much of Earth's population" by Martian forces. The set was called "Mars Attacks." Many parents, unsurprisingly, hated it. Some three decades later, it inspired the Tim Burton film of the same name.

"They were pretty violent," writes Ron Kretsch over at Dangerous Minds. "Even by today's standards some of these are a little much, but in 1962 parents were freaking the hell out."

Above: "A short synopsis of the story" appeared on the back of card 55 | Via PSA

The parental outcry was so strong that the cards were quickly pulled from shelves, in spite of Topps's mitigating efforts. Some background, via Professional Sports Authenticator (an authentication service for sports autographs and memorabilia, but, given that the Mars Attacks set has become "one of the collecting hobby's most coveted non-sports series," the collection is definitely in PSA's wheelhouse):

Cards depicting burning flesh, buxom women and dogs being zapped by aliens are bound to create an uproar, even today. The brainchild of Len Brown and Woody Gelman, this 55-card set conveyed the story of ruthless Martians attacking Earth.

At one point, Topps reportedly made efforts to tone down 13 of the most controversial cards, but after a complaint from a Connecticut district attorney, production was stopped completely. The commotion created by this set must have been somewhat surprising for Brown and Gelman, who previously collaborated on the equally gory 1962 Civil War News set.

"Topps had produced the Civil War News set prior to the Mars Attacks and it was a very popular set. Topps had just as much gore in that set as they had in Mars Attacks. But because it was a historic thing, teachers and parents overlooked the gore and said, 'Oh this is historic. Kids are reading from these cards. The cards are kind of bloody, but kids are learning history,'" said Mertes, noting that some of the stories on the Civil War cards were fictitious.

I haven't been able to track down a specific record of the cards Topps tried to "tone down," though it's hard to imagine the especially violent and rapey subject matter of cards 19, 36, 17, and 21 didn't earn them a spot on the list:

You can view the entire 1962 collection in one place here, andDangerous Minds has highlighted some more cards from the original set likely to have caused a stir. For even more Martian carnage, see this roundup of the "20 Most Twisted Mars Attacks Card" – some of the most graphic entries in the list appeared in anniversary sets re-released by Topps in 1994 and 2012.

H/t Dangerous Minds