User:Locoman/Sandbox:Crossovers
G.I. Joe
The two most prominent members of the Hasbro stable in the years of television deregulation, it didn't take long before the two franchises collided in the pages of Marvel Comics in 1986; from there, G.I. Joe would go on to become one of the most frequently crossed-over intellectual properties with the Transformers.
G.I. Joe and the Transformers (1986)
The comic that started it all, G.I. Joe and the Transformers was set in the Marvel Comics continuity and featuring the forces of Cobra and the Decepticons clashing with the Autobots and Decepticons for control of Power Station Alpha. While the series would tightly tie into the ongoing Transformers continuity, Joe author Larry Hama would largely ignore the events of the series, and would go so far as to declare the Transformers a fictional toyline in "his" version of the G.I. Joe comics...
G.I. Joe (1993)
...Despite this, however, the ongoing G.I. Joe comic would once again feature a brief crossover story with the Transformers, in which Cobra Commander formed a temporary alliance with Megatron to procure Cybertronian technology. The stories went their own separate ways again, however, and although some early issues of the Generation 2 comics would feature the G.I. Joe characters, the comic's depiction of various Earthside apocalypses made them largely incompatible with Hama's Joe output.
G.I. Joe vs. the Transformers (2003)
Published by Image Comics and Devil's Due Press, G.I. Joe vs. the Transformers was set in an original continuity with an irreverent, lighthearted tone that combined elements from both G.I. Joe and Transformers lore. The series spawned two sequels: G.I. Joe vs. the Transformers II, a time-travelling adventure, G.I. Joe vs. the Transformers: The Art of War which featured Serpent O.R., and, finally, G.I. Joe vs. the Transformers: Black Horizon, which featured the arrival of Unicron.
Transformers/G.I. Joe (2004)
During Dreamwave Productions tenure of the Transformers license, Transformers/G.I. Joe reimagined both franchises in a World War II setting. The series would have received a sequel series, Divided Front, though the collapse of Dreamwave meant that only a single issue would see publication.

