Reiner Braun is a graduate of the 104th Cadet Corps and a former member of the Scout Regiment. He ranked 2nd in his class and was regarded by others as a charismatic and a reliable big brother-like figure. He is rarely seen without Bertholdt Hoover, his close childhood friend, both of whom originate from an unknown area which he refers to as his hometown.
Along with Bertholdt and Annie Leonhart, he is a person that possesses the ability to transform into a Titan, with his being the Armored Titan. In the year 845, he used his power to help Bertholdt breach Wall Maria and infiltrate the military for currently unknown reasons.

Human Form

Reiner has short blond hair, gold eyes, and a defined facial structure. His large height, broad shoulders, and serious expression give him an intimidating presence. As a member of the Scout Regiment, he wears the wings of freedom jacket over his standard military uniform, with a green shirt underneath. In casual attire, Reiner wears a dark gray button-down shirt with rolled up sleeves and dark green pants with a brown belt.

Titan Form

Reiner's Armored Titan form is 15 meters tall and has plates of hardened skin covering the entirety of its body, except for muscles in its cheeks that become exposed when it opens its lipless jaw, as well as the muscle tissue behind its knees, elbows, and feet. Its eyes are covered by white, organic lenses, and it has short, blond hair. While fighting Eren, it has been noted that it has high agility and is capable of moving at a fast momentum, despite its seemingly-heavy weight and being low on stamina.