Kenny Ackermann was the captain of the Anti-Personnel Control Squad in the Military Police Regiment, ironically contrasting with his past as a notorious serial killer of the MPs, earning the infamous title “Kenny the Ripper.” Though feared for his brutality, Kenny became closely tied to the Reiss family after meeting Uri Reiss, seeking the power of the Founding Titan for himself. He was also the maternal uncle of Levi Ackermann and raised him briefly after the death of his sister, Kuchel. 

Kenny had shoulder-length brown hair, piercing gray eyes, and a thin beard. Tall and slim with an athletic build, he retained his agility and strength well into middle age. His attire usually consisted of a white shirt, black vest, pants, and his signature fedora hat. In combat, he wore specialized Anti-Personnel Maneuver Gear and a dark trench coat, always carrying a short blade. Kenny’s expression was often stoic, but he revealed his excitement with a wide, maniacal grin in battle. 

Kenny was cold, calculating, and ruthless, yet carried himself with a strangely jovial and mocking demeanor. He took pleasure in taunting opponents during fights, using humor and intimidation as weapons. His driving motivation was power and renown, caring little for loyalty or morality. Despite this, Kenny showed respect and admiration toward individuals like Uri Reiss and Traute Caven. His loyalty to family, though veiled, was evident: he protected his grandfather, and chose to raise Levi instead of abandoning him.

Beneath his confidence, Kenny admitted he was “trash,” revealing his self-loathing and lack of empathy. His pursuit of power was also philosophical—he wondered if gaining the Founding Titan’s power could allow even a man like him to understand compassion and kindness. 

Kenny was born and raised in the Underground, a crime-ridden city where poverty ruled. In his youth, he murdered over 100 MPs, earning his bloody reputation as Kenny the Ripper. After learning the true Royal Family was the Reiss clan, he confronted Uri Reiss, but was humbled when Uri showed compassion and spared his life. Deeply moved, Kenny swore loyalty to Uri and worked for the monarchy. During this time, he discovered his sister Kuchel’s death and took in her son Levi, teaching him survival before abandoning him once Levi was self-sufficient.

Years later, Kenny became captain of the Anti-Personnel Control Squad, leading a unit tasked with maintaining the crown’s power. Secretly, his goal was to obtain the Founding Titan’s abilities, believing it might change his perspective on life. During the battle within the Reiss Chapel, Kenny was gravely wounded. Before dying, he revealed to Levi fragments of his past and entrusted him with the decision of whether or not to inject himself with Titan serum. Kenny’s death closed the chapter of a man caught between bloodlust, ambition, and a hidden desire for humanity.