G.I. Joe And The Transformers was a limited series comic book from Marvel Comics that first combined characters from Hasbro's G.I. Joe and Transformers franchise, meeting together for the first time, and establishing a shared universe, and published in 1987. G.I. Joe And The Transformers was written by Michael Higgins and drawn by Herb Trimpe and Vince Colletta. The series was later collected in trade paperback form by Marvel in 1993, and then again by IDW Publishing in 2012 and also included in the 8th and final volume of Transformers Classics before IDW lost the license to both Hasbro franchises, news that was broken by Bleeding Cool last year.
G.I. Joe And The Transformers saw the G.I. Joe team and the Transformers' Autobots joining forces to stop the Decepticons and Cobra's joint alliance. Notably, the comic book series also saw the Bumblebee character destroyed by G.I. Joe and rebuilt as Goldbug. Eventually, Cobra would be forced to ally with GI Joe and the Autobots to stop the Decepticons from activating an energy drill device to suck up energy from the Earth's core, which would have caused the Earth to explode.
It is believed that at some point, Hasbro will be able to resist a movie with GI Joe and Transformers, as allies or at odds, and they have already run mashed-up toylines. But this comic book from 1987 was where it all began and remains one of the first cross-franchise mashups like this, which are now far more common. The first issue is currently going under the hammer today from Heritage Auctions in a 9.8 CGC slabbed copy, with bids currently totalling $134.
G. I. Joe and the Transformers #1 (Marvel, 1987) CGC NM/MT 9.8 White pages. Herb Trimpe and Vince Colletta cover and art. Overstreet 2022 NM- 9.2 value = $20. CGC census 9/22: 85 in 9.8, none higher.