There has been a lot of cut content discovered in video games over the years, such as the unused rockslide in Final Fantasy 7 or the battle royale ceremony in Dark Souls 3. One of the strangest pieces of cut content involves a Super Saiyan version of Gohan that would have debuted in a Dragon Ball video game before the manga.
Dragon Ball Z: Super Saiya Densetsu was the first Dragon Ball Z video game released for the Super Famicom. It was a turn-based RPG that started with Raditz's arrival on Earth and ended with Goku's battle with Frieza on Namek. The game used a lot of filler characters to pad its runtime, and it was possible to deviate from the story of Dragon Ball, such as by saving the Z-Fighters (except Piccolo) from dying during the Saiyan fight. This meant that the player could bring Chiaotzu, Tien, and Yamcha with them to Namek. There was also a secret post-story boss battle against Super Saiyan Vegeta, who transforms on Namek, instead of years later, as happened in the manga/anime.
It seems that the developers had intended for another character to transform into a Super Saiyan earlier than in the source material. According to The Cutting Room Floor, there is a cut character portrait that depicts Super Saiyan Gohan, suggesting that he would have also transformed at some point in the game. In the Dragon Ball manga, Gohan didn't transform until the Android/Cell Saga.
What makes this cut portrait so intriguing is the timing. Dragon Ball Z: Super Saiya Densetsu was released in Japan on January 25, 1992. Gohan didn't transform into a Super Saiyan in the Dragon Ball manga until Chapter 382, which was released on July 14, 1992. The chapter was adapted into an anime episode in October of the same year. If Super Saiyan Gohan had appeared in Dragon Ball Z: Super Saiya Densetsu, then it would have pre-dated his canonical first transformation in the manga.
This leads to the possibility of the transformation being cut at the behest of Akira Toriyama. We know that he was involved with the Dragon Ball video games, as he would create characters for them, like Majin Ozotto and the MB Army. It's possible that Toriyama requested that Super Saiyan Gohan be cut from the game, as he was planning on introducing him in the manga, and wanted the debut to happen in the comic. Vegeta had already transformed into a Super Saiyan a year earlier in the manga, which explains why he was allowed to do so in the game.
It's unclear exactly how Super Saiyan Gohan would have fit into Dragon Ball Z: Super Saiya Densetsu, but we can guess based on the events of the story. The bonus battle against Vegeta only occurs if Vegeta survives the final boss battle against Frieza, and Goku successfully transforms into a Super Saiyan. It's possible that Gohan would have transformed under similar circumstances, such as the other Z-Fighters dying in the boss battle against Frieza.
The Dragon Ball Z fans were spreading "What-Ifs" about the story since the days when the anime was first broadcast in English, and the video games have leaned into these ideas. Dragon Ball Heroes is just fanfiction with a budget, as are the Xenoverse games. The Dragon Ball video games had to come up with additional content since the days of the NES, in order to pad out their runtime, which led to similar fanfiction-style scenarios. Dragon Ball Z: Super Saiya Densetsu already played with the canon of the series in interesting ways, but it could have ended in an even more awesome fashion, like a three-way Super Saiyan battle on Namek.
Source: The Cutting Room Floor