Yu-Gi-Oh! Episode 8: "Everything's Relative"
Ghost Kaiba, known in the Japanese version as The Death Imitator, and in the English video games as the Mimic of Doom was one of Pegasus' hired Eliminators (Player Killers in the Japanese version). He replaces the Ventriloquist of the Dead from the manga. In the English anime, he was disguised as Kaiba's evil side, which Yami Yugi separated from Kaiba and banished to the Shadow Realm, but was brought back as a separate being by Pegasus.
In the Japanese version, he was either an extremely talented master of disguise or, more likely, a shapeshifter. He even seemed capable of altering his own body weight. His true form was that of an ugly, obese clown who dressed up as Kaiba to duel Yugi Muto.
He claimed that Kaiba was dead and that he was Kaiba's ghost back for revenge. In the English anime, he said he was Kaiba's evil half that Yugi sent to the Shadow Realm. The Imitator had taken Kaiba's Deck and used it in the Duel.
In the meantime, the real Kaiba, having survived his encounter with Pegasus's goons, began to hack and find out about the Duel. Yugi defeated the first "Blue-Eyes White Dragon" using a combination of "Dark Magician", "Magical Hats" and "Spellbinding Circle", but the second Blue-Eyes White Dragon destroyed "Dark Magician". Kaiba hacked into the duel arena to weaken this dragon, and the third Blue-Eyes White Dragon still in the deck. After seeing this, and then the dragon suddenly being destroyed, Yugi realized that Kaiba was still alive and demanded to know the impostor's true identity.
He began playing monsters in defense mode until he found the final "Blue-Eyes", but Yugi revived one of the other "Blue-Eyes White Dragons" and raised its power with "Mystical Elf" and "Book of Secret Arts", using it to destroy Ghost Kaiba's final dragon and wipe out his remaining Life Points. Yugi defeated him and used a Mind Crush to banish him back to the Shadow Realm for good. In the Japanese version, he used the Millennium Puzzle's power to make him disappear off the face of the earth. Despite Yugi's victory, Kemo took Mokuba back to Pegasus.
|Yugi Muto/Yami Yugi||Lose|
Ghost Kaiba used Kaiba's Deck, which was stolen by Pegasus' henchmen.