Armin Arlert (Armin Arlelt in the english dub) is a fictional character in the Attack on Titan franchise. He is Eren Yeager's childhood friend who joins him in the Scouts. He has an inferiority complex, believing he barely passed the combat graduation exam (but was top of the class academically), and whining that he hates being cowardly and having to rely on friends all the time. Despite his self-perceived shortcomings, he helped his friends on numerous occasions.
Armin is voiced by Marina Inoue in the Japanese anime dub. The English dub spells his last name Arlelt, and Josh Grelle voices him. In the live-action feature film, Kanata Hongō plays Armin. Inoue describes Armin as "withdrawn but slowly grows to the point where he's able to say what he believes". More: en.wikipedia.org.