Marco Bott was a trainee of the 104th Training Corps and graduated as the seventh highest ranked trainee in his class. He was assigned to fight Titans during citizen evacuation after the breach of Trost District and was given command of his own squad.
Marco was of above-average height with a broad, muscular build. He had short, parted brown hair, freckles, and light brown eyes. He wore the typical uniform of a member of the 104th Training Corps.
Marco was an idealistic person, valuing the good of the group above his own interests as well as understanding and coping with his own shortcomings and limitations. The others respected him greatly and considered him to be a natural leader suited to his dreams of joining the Military Police Brigade. Unlike those who joined the Military Police Brigade for safety and privileges, his reasons for wanting to join it were genuinely faithful to the king. He was shown to be an excellent judge of character, as he recognized Jean's potential as a leader and encouraged him to believe in himself. He was also shown to have a talent for preserving order among the other trainees, whether resolving arguments or keeping them calm during battle. Even when frightened, he still retained a relatively calm demeanor. Marco was often a voice of reason, even trying to talk things out right before his death.
Appearance: Marco was of above-average height with a broad, muscular build. He had short, parted brown hair, freckles, and light brown eyes.
Personality: Marco was an idealistic person, valuing the good of the group above his own interests as well as understanding and coping with his own shortcomings and limitations. The others respected him greatly and considered him to be a natural leader suited to his dreams of joining the Military Police Brigade.
Marco Bott in the story: Marco is first introduced during the initiation of new recruits and is intimidated by their instructor after he expresses his desire to join the Military Police. Following the initiation, Marco joins the other trainees in watching Sasha Blouse as she runs laps around the camp as punishment for eating during the ceremony. As they go to eat, Marco notes that Eren Yeager was not affected by Shadis' harassment, and Eren reveals that he is a survivor from Shiganshina District.
How Marco Bott echoes later: After Marco's death, Jean is inspired to abandon his selfish ways and join the Survey Corps, claiming that he does not want to meet a "disappointing end with someone burning his bones without knowing who they belonged to," referencing how Marco "died alone" and went unnoticed for days. Jean reveals the news to Eren, who is horribly shocked, and Eren briefly reminisces about his time with his former friend. Later, during the attempted capture of Annie Leonhart in the Stohess District, Marco's vertical maneuvering equipment is found to have been taken by Annie, as Armin remembered the little tweaks it had as he and Marco performed their equipment maintenance together.
Source: Attack on Titan Wiki, available under CC BY-SA 3.0.