Kenny's grandfather

Kenny's grandfather was the grandfather of Kenny and Kuchel Ackerman and the great-grandfather of Levi Ackerman. He was one of the few living remnants of the Ackerman bloodline with knowledge about the reasons for the persecution of his clan.

Appearance
He was a sickly and frail old man, with limp, light-colored, neck length hair. He had weary eyes, a pointed nose, and a mustache that formed into a beard. Due to his health, he wore loose fitting clothes and appeared unable to leave his bed.

Personality
In an attempt to protect current and future members of the Ackerman family, he intended to die without ever telling anyone the secrets of the Ackerman bloodline's previous life by the King's side.

The Uprising arc
On his deathbed, Kenny Ackerman visited him, for what would likely be the last time. He told him that he found his sister, Kuchel Ackerman, and that she was impregnated by a customer. He also informed him that the Military Police that were snooping around had been taken care of.

Baffled at the state the Ackerman family was in, he questioned his grandfather about how things came to be that way. In an attempt to sweet talk him he went on to say, "I'm your cute little grandson, aren't I?" Gasping, he sat up and asked if the cute little grandson he knew was known in the capital as "Kenny the Ripper." Though originally intended to keep the Ackerman secrets to himself, seeing the state that the Ackerman family was in, he began telling Kenny what he knew.

He started off by clarifying that the royal government did not hate the Ackermans, but feared them instead due to the King's inability to control them. He went on to say that despite being born within the Walls, he was certain that they served at the core of the royal government; with the duty of ensuring humanity's continued survival. He mentioned how most of humanity was from a single bloodline, while a small group was from separate bloodlines. Because of those from the differing bloodlines, they posed a threat to his rule, the king was unable to see his ideals come to fruition.

The King's ideal rule was to rewrite humanity's memories by erasing the history of the past in order to bring about peace and order. When Kenny became confused at the mention of erasing memories, grandpa Ackerman flatly stated that was is the power of the Titans. Maintained by the monarchy, the Titan's power had been passed down from generation to generation. A power so strong, it was used to create the Walls, and erase the history of life outside them for the vast majority. Despite this, it had limitations, and had no effect on the minority bloodlines; including the Ackermans. So in order for the King's ideals to be realized, the minority bloodlines needed to be, in some way, silenced. Only two of the bloodlines opposed the King, they gave up their positions and turned their backs on the royal government.

He went on to say that originally the truth was kept from his generation as well, in an attempt to protect them. But the head of the family offered and sacrificed his own life to preserve the lives of remaining members of the Ackerman family, which ultimately proved to be pointless. For a moment Kenny was silent, he decided he believed his grandfather's story; because it would be more fun that way.

Relationships

 * Kenny Ackerman - Kenny was his grandson and their relationship was complicated. Although he seemed to love Kenny, he also rejected what he had been doing with the Military Police, saying how he was the monster of the capital. However, he also trusted Kenny as far as to revealing him the secrets of the persecution of the Ackermans.
 * Kuchel Ackerman - As his granddaughter, it is supposed that he loved her and worried about her. During his last meet with Kenny, the boy told him the situation of Kuchel, being afraid of that could hurt him. However, the latter did not have any reaction after hearing the news.

Trivia

 * Hajime Isayama stated in a Q/A that he was designed to look like Levi, with a beard.