For the longest time, western fans believed Beast Wars II and Neo to have taken place during the events of Beast Wars, due to catalogs that depict the BW and BW II cast existing in the same time, as well as Neo depicting Cybertron as still being mechanical and not technorganic.
the vehicle mode of the Legacy Elita-1 toy seems to be based on a fan artist's interpretation of her vehicle mode instead of her actual vehicle mode model from the cartoon. (2022)
Optimus totally doesn't forgive Grimlock. (1984)
Transformers "Battlin' Robots" and Walkie-Talkies. (1985)
Hot Rod/Rodimus Prime's character models underwent many, many revisions over the course of development. (1986)
the infamous Armada "Built To Rule" line of construction toys, who look like that because they're all designed around the same "trans-skeleton". (2002-2003)
Spike's harem. (2011)
in the Headmasters anime, Cybertron blows up, rendering Optimus Prime's death completely pointless. (He had sacrificed himself to stabilize Vector Sigma several episodes prior) (1987)
This VF-1EX Mirage Farina Genus machine, from Episode 3 of "Macross Delta" resembles the color scheme of the G1 Jetfire toy. (2006)
most toys and promotional material for the Bumblebee movie are based off an early design for him that differs from the final model in a few ways, most visibly by having door wings that the final design lacks. (2018)
unreleased "Sideways Sneak Attack" set, with Sideways sporting battle damage meant to replicate that scene where he got cut in half.
Optimus defeats Devastator in a single shot.
Lugnet gets kicked in the ass. (2008)
The Spanish (Latin) dubs of Cybertron and Energon are partially lost. Why they never got a DVD release like the rest of the shows is unknown. An infamous fandubber called Piero Gionti has possession of most of the chapters of the lost dubs, but has refused to release them.
the Omnibot Camshaft is called that in spite of the fact that he turns into a Mazda RX-7, which featured a rotary engine that does not actually have a camshaft. (1985)
According to a member of the Melbourne House team, the Cybertron game that would have been a sequel to the Armada game was a few months into development when Atari moved the studio onto a different project, effectively nixing the sequel. (2005)
due to the character models for the 1st and 2nd seasons of the G1 cartoon being done by different artists (Shōhei Kohara in S1, Floro Dery in S2), this results in characters with the same toy mold having completely different animation models. (1984-85)
due to the Transmetal Beast Wars toys not coming with any ranged weapons, the animators of the cartoon had to figure out on their own how to give them firearms while also incorporating aspects from the toys. (1998)
exposure to Brainstorm's meta-bomb gives Swerve the ability to break the fourth wall. (2013)