|Relatives|| Carla Yeager (wife, deceased) |
Eren Yeager (son)
Mikasa Ackerman (adoptive daughter)
|Species||Human, Titan Shifter|
|Manga||To You, 2000 Years From Now|
|Anime||To You, 2000 Years From Now|
|Anime|| Hiroshi Tsuchida (Japanese)
Chris Hury (English)
Dr. Grisha Yeager (グリシャ・イェーガー Gurisha Yēgā?, sometimes romanized as Grisha Jaeger) was a doctor who lived in Shiganshina District before it fell, and was acknowledged for saving hundreds of lives from a plague that hit the city.. He was the father of Eren Yeager, adoptive father of Mikasa Ackerman, and husband of Carla Yeager. He was also a Titan Shifter  and first appeared mysteriously outside the Walls.
Dr. Yeager had a gentlemanly appearance. He had straight black hair neatly parted down the middle, a light beard and mustache, and gray eyes. He wore a gray suit with a black vest and a white shirt, a plain bolo tie, and round glasses. In the anime his hair and eyes are both brown, and he wears a brown suit with a white cravat and a white shirt with ruffled sleeves. 
As a Titan, he had a body with a notoriously bulkier torso than his arms and legs. He had long, dark hair, elongated ears, small eyes, and his mouth was covered in flesh and a dark, thick beard along with black chest hair.
About 20 years before the coronation of Historia, Grisha Yeager was found wandering outside the Walls, near the Shiganshina District, by Keith Shadis. The soldiers were very surprised to see him, not only because he was outside the walls, but also because he suffered amnesia and he had no memories about the world inside the Walls and the military. He was taken to a cell by Keith and Hannes, where he says that he remembered his name. After being released, Grisha told Keith that he remembered being a doctor and asked him for knowledge about the world inside the Walls.
Keith takes Grisha to a pub in Shiganshina where Keith taught him about the world. Grisha recognizes the work of the Survey Corps, which surprises Keith. There, Grisha also meets Carla, his future wife. Grisha eventually found work at an hospital. He proved to be a talented medic, and his relationship with Carla grew stronger. They finally married, which made Keith very sad, as he too had fallen in love with Carla.
The day Wall Maria fell, Grisha took Eren to the forest after learning of the death of his wife. Keith tried to stop him, but Grisha just told him not to get involved. That is the last time Keith saw Grisha.
StoryMikasa Ackerman. He keeps the basement of his house locked and doesn't allow anyone inside. Before Wall Maria fell, he promised Eren that he'd show him what was in the basement when he got back from a journey.
After the fall of Wall Maria, a tearful Grisha injects a serum into Eren's left arm, which Eren believes is responsible for giving him the ability to shift into a Titan. Telling Eren that the serum will cause him memory loss, Grisha gives him the key to the basement, saying that all of the answers can be found there, and that "their memories will guide you." Grisha then disappeared, and was not seen for the next five years.
After Eren finally succeeds in the use of 3D Maneuver Gear, head instructor of the 104th Trainees Squad Keith Shadis expresses to himself that Grisha would be proud of his son, Eren, and that he is finally becoming a soldier.
When Eren transforms into a Titan, during experiments conducted by Hange, they ask him to try and communicate with them and the other Survey Corps personnel. He writes on the ground that he doesn't know how to harden his body. He then sloppily writes, "My father... to me," referring to Grisha. As he rests after the experiment, Eren wonders where his father is and why he thought of him at that moment.Wall Maria after the Colossal Titan breaches it, Keith Shadis is visible a few steps ahead of Grisha and looking back at him. Then we see Grisha moving toward the chapel that then stood above ground over the cavern, finding his way underground, and pleading with the gathered members of the Reiss family: Rod, his wife, and their five children. He then transformed into his Titan form and killed every Reiss except Rod, who escaped, and Historia, who was not present. During this attack, he battled at least one other Titan, a female, whom he ate. He then destroyed the chapel. Later, in the woods, he gave 10-year-old Eren the key to their basement in Shiganshina. He then injected Eren with a serum that caused him to transform into a Titan. The transformed Eren consumed Grisha, reverted back to his human form, and began to wail in horror at the grisly remains of his father.
Rod later reveals that Grisha confronted the Reiss family in the chapel with a frightened expression on his face. His daughter Frieda Reiss stood in front of her family, protecting them. Grisha then stabbed himself through the hand with a knife and transformed; Frieda shifted by biting her hand. Rod states that Grisha was after Frieda's Titan power, and though it was "invincible," she was not experienced enough to defend herself. Grisha ate her, obtaining that power, and then brutally slaughtered the remaining Reiss family. Among the victims were 14-year-old Dirk and 12-year-old Abel, both of whom Grisha crushed with his hand. He also stomped on 10-year-old Florian and the girl's mother, and squeezed Rod's eldest son Ulklin to death. Finally, he destroyed the chapel. Rod was the only one who managed to escape.
It is later stated that he stole the power from the Reiss family because as long as they were the users of the Coordinate, none of them would ever stop the Titans, even when they have the power to do so and the only hope to use the Coordinate against the Titans was giving the power to a member of another bloodline.
After Eren received more memories of his father thanks to Historia, he searched for the man that his father met the day Wall Maria fell. Eren finally realizes that he is Keith Shadis.
Grisha was a very skillful doctor, being able to cure hundreds of people from a sickness that attacked mankind. When Carla got sick, he not only could cure her, but also her family. Grisha also was able to find a medicine that could stop said plague.
Grisha Yeager's Statistics :
Grisha could turn into a 15 meter Titan; it appeared that he had all of the regular abilities of Titan Shifters, like extraordinary regeneration, incredible strength, and endurance when he is transformed. Other than these, it is unknown if he had any other unique abilities. He had some experience with Titan Shifting; that was the reason why he managed to kill and eat Frieda Reiss, a Titan Shifter that almost matched his size and possessed the Coordinate. He stabbed his own hand with a knife in order to trigger the transformation.
- The Coordinate: After eating Frieda, he possessed this power for a very short amount of time. However. he did not make use of it before passing it on to Eren.
- Regeneration: As a Titan Shifter, it is believed that he could regenerate his body faster than regular humans, even from fatal wounds.
- The appearance of Grisha's Titan may be a reference to the giant Surtr of Norse mythology. According to mythology, he is the leader of the fire giants in the south, the ruler of Muspelheim, and at Ragnarok his hordes will rush to the north like a southern wind to overwhelm the gods.