|Only one eye?! It prioritized one eye to accelerate the healing… Is that even possible?|
|— Petra's last words.|
Petra was a relatively short woman with blonde hair and blue eyes. She wore the typical uniform of a member of the Survey Corps, with a white button-up shirt underneath.
Petra was kind and caring, as shown when she looked after and guided Eren when he was first admitted to the squad. She seemed to have acted as some sort of attachment figure for Eren among Levi's Squad as she was the one shown to worry about him. Although all of Levi's squad wished (and demanded, to an extent) Eren's unconditional trust, it was ultimately Petra who convinced him to do so.
Despite her kind nature, Petra was a conditioned soldier with a quick reaction time against perceived danger, such as the time when Eren accidentally transformed into a half Titan, she took an extreme reaction and interrogated him alongside her squad. She also displayed extreme loyalty to her leaders and superiors and their orders.
She also showed the most remorse over her reaction to Eren's accidental transformation. Along with her comrades, she had bitten her hand just like Eren, signifying that they had established a close bond.
StoryWall Rose, tending to a critically injured soldier. When she is unable to stop the bleeding, she helps Levi comfort their dying comrade and mourns his death.
She is later revealed to be a member of the Special Operations Squad, or Squad Levi, and is ordered to guard Eren Yeager. It is established that she greatly admires Levi, and argues frequently with Oluo Bozado over his imitation of their commander and his harsh behavior.
While initially wary of Eren and quick to draw her swords when he transforms by accident, she readily accepts him afterwards. She is the first of the group to bite her hand in imitation of Eren's method of transforming, and notes that doing so is actually quite painful. She serves as a gentle, almost maternal presence within the squad and discusses with Eren the importance of trusting one's comrades completely.When the Female Titan begins her attack on the 57th Expedition, Petra is one of those most vocal about Eren avoiding battle. She repeatedly begs him to trust in his commanders and comrades, and accept the sacrifices of others so that the mission can keep going. Eren eventually makes the decision to follow her advice, allowing the Survey Corps to successfully capture the Female Titan in a trap. Afterwards, the Special Operations Squad climb to one of the giants trees and is ordered to standby while efforts are made to capture the human within the Female Titan. However, the operation ends in failure because the Female Titan uses a scream to summon other Titans to her position and is devoured by them.
Afterwards, the squad begins to retreat back to their horses, when a flare leads them off-course. They are then ambushed by a person later revealed to be Annie Leonhart, who murders Gunther Schultz before she transforms back into her Titan form. Eren is ordered to flee while the surviving squad members engage the Titan in battle. Petra and the others initially have the upper hand since they blind the Female Titan with the vertical maneuvering equipment's gas and cripple both her arms, making them useless. But when Petra and Eld Jinn move in for the kill, the Titan suddenly regenerates a single eye (demonstrating a previously-unknown ability to focus healing into fewer body parts to speed up the regenerative process as a defensive tactic) and bites Eld in half, killing him.Paralyzed from shock and despite Oluo's pleas, Petra is unable to react in time to the Female Titan's kick, which breaks her spine and splatters her against a tree. Her corpse is seen by Levi with a silent expression when he tracks down the Female Titan. Levi would release his fury later while fighting with the Female Titan.
Her father comes to greet her when the troops return, and he appears to be nervous and tense when approaching Levi (presumably because he had yet to catch sight of her). He reveals that Petra wrote to him constantly, saying that she had great pride in being selected as a member of the Special Operations Squad. The contents of her letters suggest she may have been overly eager to excel in her career as a soldier, and this led her father to express worry over his daughter's safety. He implies that he would like her to settle down and get married, though he freely admits that she is still too young for a serious relationship. Levi listens to him in silence with a vacant, mortified expression on his face.
Later in the Battle of Shiganshina, as Erwin Smith begins to lament the dwindling hopes of his dream, Petra stands among the many fallen Survey Corps comrades in Erwin's mind, wanting to know if their deaths had meaning.
AbilitiesShe was a skilled and experienced warrior using the vertical maneuvering equipment and had a high kill record of Titan kills (58 Titans killed, 48 in team and 10 in solo), being one of the highest known in the series so far. For that reason she was handpicked by Levi to take part of the Special Operation Squad. Her coordination with Oluo and Eld was almost perfect, as they were close to defeating the Female Titan by themselves.
Petra Ral's Statistics :
- Levi Ackerman - Petra expressed great admiration for her captain, and criticized Oluo for imitating him. She noted that many people are surprised upon actually meeting him and admitted that he does not live up to the legend of 'Humanity's Strongest Soldier' due to his many personality quirks and flaws. Her relationship with him is portrayed somewhat differently between the manga and the anime adaptation. In the manga, it was revealed after her death that she wrote to her father about her wish to live up to Levi's expectations and dedicate herself to her career. Her father expressed his worry over her safety to Levi, as well as his disappointment that she did not seem to want to marry, despite acknowledging that she was still too young. In the anime however, she declared her intention to devote her life to Levi in their correspondence.
- Eren Yeager - Initially, she was uneasy around him and drew her swords on him when he accidentally transformed. However, after learning that it was a mistake, she apologized for her behavior and bit her own hand to acknowledge him as a comrade. She quickly took him under her wing, and acted as an almost maternal figure during his month with the Special Operations Squad. During the mission in the forest, she repeatedly asked him to place his trust completely in his comrades and wished for him to believe in her. Petra's death deeply affected Eren.
- Oluo Bozado - Petra and Oluo were frequently at odds, often bickering with each other. She was highly critical of his attempts to imitate Levi, and demanded that he stop. She also stated that he should bite his tongue off and die. However, beneath this seeming-hostility was a strong bond of trust born from their many missions together. He also told Petra, "You're still ways to go to be fitting for my wife." His horror after her death, and attempts to mimic the man she admired hints that he may have harbored feelings for her.
- Eld Jinn and Gunther Schultz - As comrades, she had great faith in them and cared deeply for her comrades. She was enraged after Gunther was murdered, and repeatedly challenged the Female Titan while swearing revenge. Eld's death similarly shook her and caused her to panic and freeze, which eventually led to her death.
- Petra was the only female in the original Special Operations Squad led by Levi.
- Her name is Greek in origin, written "Πέτρα" and meaning "rock" or "stone". it is also the name of an ancient city in the region that is now Jordan.
- Her 58 total Titan kills is the highest confirmed so far in the series; although only 10 have been in solo and 48 in team (a record too). In solo, the record belongs to Oluo with 39. Nevertheless, Levi as Humanity's Strongest Soldier is assumed to surpass both of them, but his total statistics have not been revealed.
- According to Eld, Petra cried and soiled herself during her first Survey Corps expedition.
- The Attack on Titan Guidebook includes an imaginary interview with Petra and Oluo that supposedly takes place after they were killed by the Female Titan: 
- Q: You two came to a very shocking end.
- Oluo: I let that Titan win. You don't seem to understand: beating a Titan isn't necessarily the best way to get noticed.
- Petra: The Female Titan was a tough enemy, so I can't be surprised at what happened. But if the captain was in that situation...
- Oluo: Hah. With the right methods, there's nothing I can't defeat—
- Petra: Hey! Are you trying to imitate the captain yet again?!
- Oluo: You're the one who followed me, Petra. But don't you think it's a little early to be acting like my wife?
- Isayama has stated that Petra and Oluo were from the same batch of trainees.