Boris Feulner (ボリス・フォイルナー Borisu Foirunā?) is a member of the Military Police Regiment stationed in Stohess District. He is a graduate of the 104th Cadet Corps, though he is not from the same division as Eren Jaeger.
Boris has short silver-blond hair combed to the left and pale yellow eyes. He is commonly seen wearing the Military Police Regiment uniform with an off white button up shirt underneath.
Through appearances Boris seemed to be prudent, pragmatic and pessimistic. He does not enjoy picking fun or laughing a lot, shown when he halted Marlo Freudenberg and Hitch Dreyse from giving Annie Leonhart a hard time and when he did not join Hitch in laughing or even smiling at Marlo's ambition. However, he does not appear completely serious as he does humor Marlo's goals and sarcastically wishes him luck.
Boris comes to Annie's defense when she is late for duty, arguing that being the only one with real combat experience as she was deployed in Trost District, Annie must be still suffering trauma from it. When Hitch claims he likes Annie, Boris quickly silences her by pointing out her own flaws and implies she only got into the Military Police through improper and dishonest means. They are then given their assignment for the day by their senior officer.
Later, all the rookie MPs gather outside, waiting to start the mission. Hitch and Marlo call their senior officers conceited which causes Boris to challenge Marlo, saying that he is probably no better because he also chose to join the MPs. Marlo states that he intends for the higher-ups to compensate for their misdeeds. Boris sarcastically wishes him luck.
When Marlo decides to confront two superior officers for illegally selling government equipment, Boris watches and remarks how it should make for a nice entertainment.