Samuel is a member of the 104th Trainees Squad. He appears in Ch. 3. When the Colossal Titan appears outside Trost District, the burst of steam from its body knocks a number of trainees off the Wall. While most are able to switch to their Three Dimensional Maneuver Gear and anchor themselves to the Wall, Samuel is struck in the head by a piece of falling rock and stunned. Sasha saves him from falling to his death by firing one of her grappling hooks into his leg. Eren tells Sasha to take Samuel somewhere safe, then instructs the other trainees to attack the Colossal Titan.

Spoiler

He is killed by Connie after being shot three times in the head.