Adrian Gecko, known in the Japanese version as Amon Garam, is a student hailing from East Academy who enters Duel Academyin the third year. Reserved and secretive, Adrian is a neutral character whose actions seem to only serve the Gecko Family and himself. However, after obtaining the spirit of "Exodia the Forbidden One" in the third alternate dimension by sacrificing Echo, he intends to rule it and acts as a secondary antagonist towards Jaden and the primary antagonist, Yubel. After being defeated, he felt remorse for sacrificing Echo as he was in love with her. He is one of the few characters who did not return after Jaden defeated Yubel.
Unlike most Yu-Gi-Oh! muscle men, Adrian actualy uses his physique for physical combat, making him one of the few muscle men that aren't Muscles For Show.