If you're only familiar with the 4Kids dub of Yu-Gi-Oh!, you've missed out on a lot of gruesome content. Even if you watch the anime with subtitles, you're only getting a small portion of the graphic content the series has to offer. In the manga, things get very disturbing. It's amazing this story was ever marketed to children.
Dark moments from the Yu-Gi-Oh! manga include self-harm, aggression toward others, forced hallucinations, and more. Yu-Gi-Oh! fans with a low tolerance for horror might want to leave this series on the shelf - but those with a penchant for creepy manga might just end up loving it.
Yu-Gi-Oh! isn't the only manga with a far more cheerful anime counterpart, but it's one of the most memorable.
Pegasus meets a gruesome end in the manga. At the conclusion of the Duelist Kingdom arc, Yami Bakura rips Pegasus's Millennium Eye out, instantly putting an end to his life.
Pegasus reappears several times in the Yu-Gi-Oh! anime and its sequel series, Yu-Gi-Oh! GX and Yu-Gi-Oh! 5D's. In the manga, however, he remains in his grave.
You wouldn't know it from simply watching the Yu-Gi-Oh! anime, but Bandit Keith actually meets his end in the manga. In the anime, Keith threatens Pegasus as a response to his humiliation following his loss to Joey in the Duelist Kingdom tournament. Pegasus opens a trap door and sends Keith plummeting to the rocky sea below - but he somehow survives.
In the manga, there's no trap door. Keith threatens Pegasus, and Pegasus responds by using mind control to force Keith to take himself out. Keith even does the deed with his own hand, which is turned into a side arm.
After Yugi forces Seto Kaiba to hallucinate about his own neverending demise, Kaiba is understandably furious. His response, however, is wild. Kaiba creates a theme park designed to defeat Yugi and his friends in one of several cruel games. In one game, he forces them to go through a haunted house while wearing helmets that will electrocute them if they make a single sound.
In another, Kaiba's brother Mokuba accidentally eats a toxic meal meant for Yugi and his friends.
In both the anime and manga versions of Yu-Gi-Oh!, Seto Kaiba overthrows his stepfather Gozaburo Kaiba as the CEO of KaibaCorp. Gozaburo isn't happy about it in either version, but in the manga, he tells the young Seto that he's about to show him what happens to losers. He then throws himself out the window.