|Eren! You'll understand the truth someday, if you visit the basement! It will be a harsh, painful journey...but you must reach it! If you want to save Mikasa, Armin, and everyone else...you must learn to control this ability!|
|— Grisha shortly before injecting Eren|
Dr. Jaeger has a gentlemanly appearance. He has straight brown hair and brown eyes with circular glasses. He wears a brown suit with a white cravat and a white shirt with ruffled sleeves. He has also been seen wearing a small, black hat with a gray stripe.
Although much is unknown about his motives, he appears on the surface to be a rather calm, calculated man, Grisha's most notable character traits are his hard-headed personality and his intense passion for whatever cause he dedicates himself to.
Years before the fall of Wall Maria, Grisha Jaeger was making a house call, with Eren tagging along, to Mr. Ackermann and Mrs. Ackermann for an appointed medical examination in the year 844. When he arrived there, he found them dead for hours. He asked Eren if he had seen the girl named Mikasa anywhere, but he was too shocked to answer. He then told Eren to wait for him at the foot of the mountain while he finds the Military Police. After the MPs and Grisha arrived at the murderers' hideout, Grisha hugged Eren and scolded him for the murders he committed when saving Mikasa, asking if he even understood what he had done. However, instead of continuing to scold him for killing Mikasa's kidnappers, he told him that this time he was lucky and he could have been killed himself. Mikasa, cold and depressed, asked Grisha in what direction her home was and stated that she was cold and wants to leave. In response, Eren gave her his scarf and Grisha told her to come live with them.
Upon learning from Mikasa that Eren wants to join the Scout Regiment, Grisha is more obliging of the idea than Carla, asking his son why he wants to leave the Walls. Upon hearing his son's answer, Grisha announces that he will be departing, telling a bewildered Carla that there is no point in trying to stop an inquisitive mind like Eren's. Before he leaves, he promises to show Eren what he has been hiding in their basement when he returns.
After Eren finally succeeds in the use of omni-directional mobility gear, head instructor of the 104th Cadet Corps Keith Sadies expresses to himself that Grisha would be proud of his son, Eren, and that he is finally becoming a soldier.
During his interrogation with Kitz Woermann, Eren Jaeger recalls meeting his father on the night of the fall of Wall Maria. During this time, Grisha gave Eren the basement key and forced him take an injection that causes him to lose his memories. He told Eren that he must get to the basement and spoke of the hardships he will face. Grisha was adamant that Eren must learn to control his power and save Mikasa's, Armin's, and everyone else's lives.
Grisha is a very skillful doctor, and serves many families within the Walls. He was able to cure hundreds of people from a sickness that attacked mankind before the Fall of Wall Maria, earning him respect throughout the Walls.
Grisha Jaeger's Statistics :
- Eren Jaeger - Grisha is perhaps closer to Eren than anyone else in his life, surpassing even his relationships with Carla and Mikasa. As a father, Grisha left home for a lot of medical duties, however, he encourages Eren's dreams to venture outside the Wall and offers to reveal to him the secrets of the basement.
- Carla Jaeger - When Grisha heard of Wall Maria's downfall, he shed tears in fear that his family had perished. Grisha was visibly affected by her death, and when turning Eren to a Titan, is told that her death had made him crazy as his son screamed.
- Mikasa Ackermann - Grisha knew Mikasa when she was a small child from visiting her home as the family doctor. When taking Eren along for a visit, he had hoped that the two would be able to get along as friends. After her rescue from the human traffickers, Grisha showed sympathy towards Mikasa and told her to come live with him and his family. Years later, after the fall of Wall Maria, Grisha mentions her name as he sheds tears in fear that she had been killed by the Titans.
- Mr. & Mrs. Ackermann - Dr. Jaeger was well known to the Ackermanns as their family physician. They appeared quite friendly when speaking about each other, and Grisha had been known to have been their doctor at least since Mikasa was small, however it appears that as she grew older his visits were less frequent. Grisha seemed quite disturbed at the sight of their deaths.