"Name unknown", known as the mysterious assassin (謎のアサシン nazo no asashin) in the Japanese version is a character in the Yu-Gi-Oh! manga.
He may be an homage to Golgo 13.
He was hired for the Death-T theme park at Kaiba Land, which was created to kill Yugi Mutou. The assassin was put on a team with Johnny Gayle and Bob McGuire to face Yugi and his friends in the first stage of Death-T. Each of them were promised a bounty of ¥10,000 for each opposing player they killed. The assassin planned to kill all three, so he could claim the three bounties for himself.
Gayle moved out first, saying that they should leave it to him, as he was an expert in guerrilla warfare, but Jonouchi took out Gayle by kicking him in the face, after running along the tops of the walls. Seeing this, the assassin and McGuire started shooting at Jonouchi.
Once Honda realized his team's guns did not work, he called his team back for a timeout. Honda returned by himself afterwards, dropping his gun and offering to surrender. However the assassin laughed that was no use, with the bounty for killing Honda in mind. Johji, who was hiding on Honda's back, tossed him Anzu Mazaki's operational gun, which Honda used to take out the assassin and McGuire. Since Honda had previously set the laser to a non-lethal voltage, the assassin and McGuire were not killed.
He bares a striking resemblance to Nezbitt, who also worked for Seto Kaiba.