Boris Feulner (ボリス・フォイルナー Borisu Foirunā?) is a member of the Military Police Brigade stationed in Stohess District. He is a graduate of the 104th Training Corps, though he is not from the same division as Eren Yeager.
Boris has straight ash blond hair with long bangs combed to the left. His expression is usually calm or neutral. He is commonly seen wearing the Military Police Brigade 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 Marlowe Freudenberg and Hitch Dreyse from giving Annie Leonhart a hard time and when he did not join Hitch in laughing or even smiling at Marlowe's ambition. However, he does not appear completely serious as he does humor Marlowe's goals and sarcastically wishes him luck.
Boris comes to Annie Leonhart's defense when she is late for duty, telling Marlowe Freudenberg and Hitch Dreyse to give her a rest. He states 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 Marlowe call their senior officers conceited which causes Boris to challenge Marlowe, saying that he is probably no better because he also chose to join the MPs. Marlowe states that he intends for the higher-ups to compensate for their misdeeds. Boris sarcastically wishes him luck.
- Boris ranked thirty-fifth in the Second Character Popularity Poll.