| The subject of this article has no official name.|
It is a fan-given name as substitute for lack thereof, and should not be considered as part of the Attack on Titan universe.
|Even if the entire world ends up hating you... just know that your dad is always on your side... So promise me... that you'll come back...|
|— Mr. Leonhart to his daughter, Annie|
Mr. Leonhart is the father and trainer of Annie Leonhart. He relentlessly trained Annie to fight, using mostly kicks and the attacker's weight against them. Memories of his pleas for forgiveness later create an opening for Annie to crystallize herself before Eren Jaeger has the chance to capture her.
Mr. Leonhart has a receding hairline with his blond-gray hair combed back. He appears to be a relatively short man, as his daughter is also very short, and well built for fighting as he is a trainer. He has only been seen wearing a light jacket over a white shirt with dark pants and shoes.
He seems to be a relentlessly strict trainer, not allowing his daughter to take breaks and yelling at her during the training sessions. However, sometime before Annie's departure, he has a change of heart and apologizes to her, asking her to promise him that she comes back someday, assuring her that he would always be on her side.
At some point before the fall of Wall Maria, Mr. Leonhart taught Annie fighting techniques that involved kicks and the use of the opponent's weight against themselves. Before Annie left their hometown, Mr. Leonhart apologized to her, saying that it was too late to ask for forgiveness. However, Mr. Leonhart assured her that even if the whole world hated her and treated her like an enemy, he would always be by her side. He asked her only to promise him that she will return home.
During her investigation of the disappearance of Carly Stratmann, Annie thinks back to her relationship with her father, along with the relentless combat training he subjected her to, after seeing the relationship between Carly and her father Elliot G. Stratmann.
While Annie is trying to escape from Stohess District transformed in her Titan form, she remembers the last words her father said to her before she left her hometown. This memory triggers her hardening ability, encasing her into a crystal cocoon and allowing her to avoid interrogation, although she is captured and placed underground.
- Annie Leonhart - At first he seemed to be a strict and not very approachable father for Annie, though for some reason he later changed his mind and demonstrated his love for his daughter by tearfully hugging her and assuring her that he would always be on her side. This reaction seemed to deeply surprise Annie, indicating that it was not common in him until then.