Thomas Wagner (トーマス・ワグナー Tōmasu Wagunā?) was a graduate of the 104th Training Corps who fought during the battle for Trost District and was assigned to the middle guard after the Colossus Titan's second attack.
Thomas was initially quite pessimistic about defeating the Titans, believing that humanity ultimately stands no chance, but he would later change his way of thinking after hearing an inspiring speech from Eren. As a trainee, Thomas admitted to still being a bit cowardly, as he was too frightened to immediately act upon witnessing the Colossus Titan for the first time. Despite this, Thomas was also somewhat of a leader, rallying his team into turning their first battle into a hunting competition despite the inherent uncertainty.
Thomas Wagner is introduced as hailing from the Trost District. A member of the 104th Training Corps, he first meets Eren Yeager while questioning him about the Colossus Titan. Later, he operates the training equipment for the vertical maneuvering equipment during Eren's second attempt at his aptitude test. At Keith Shadis' orders, Thomas exchanges equipment with Eren and it is discovered that Eren's equipment was defective. After graduating, Thomas planned to join the Survey Corps.
He is seen cleaning out the cannons with his comrades atop Wall Rose. When the Colossus Titan appears outside Trost District, he and his fellow trainees are knocked off the Wall by a blast of steam. Eren orders them to attack the Colossus Titan, but Thomas and his comrades are too shocked to immediately react.
After the breach, he is assigned to the middle guard along with Eren, Armin Arlert, Mylius Zeramuski, Nac Tias, and Mina Carolina. He suggests they have a contest on who can kill the most Titans. Noticing the alarming amount of Titans in the middle guard, the squad begins to advance, but an abnormal Titan surprises them, catching Thomas it its mouth and swallowing him whole, while his team mates watch in horror.
Armin would later report his demise to the remaining members of the 104th Training Corps, saying he died valiantly in the line of duty.
During the Survey Corps feast before the battle of Shiganshina District, Connie reminds Eren of the time Sasha had attempted to share stolen meat with their squad.