|Manga Debut:||TWIN HEADS Chapter 1|
Petra is a character featured in Shingeki no Bahamut TWIN HEADS.
Petra is always seen in her maid outfit and wearing round glasses.
Petra cares deeply for the well being of her young master, Jail Marginal, and spends most of her time making sure he's okay.
Petra is first shown looking for Jail in the city after losing sight of him. When she sees Favaro with Jail, she violently lashes out and tries to cut Favaro with a knife. She proceeds to hug Jail in relief and concern. When Jail confirms that Favaro is not an enemy, Petra takes Favaro back to their hideout and offers him food. They tell Favaro about their situation and what they're doing.
The trio are approached by Kaisar and a group of men. Kaisar gets into a fight with Favaro and the two run off while the men kidnap Petra and Jail. Favaro returns in time to rescue them using smoke bombs and they board Favaro's stolen caravan. On their way out of the city, masked men try to capture them but Favaro is able to knock them off their vehicle. However, the caravan gets destroyed by Violet's ice magic.
The trio are knocked into a river. Once Petra wakes up, she watches over Jail until he wakes up as well. They are gathered around a campfire and once Favaro returns with Jail's dried uniform, Jail explains his past with Violet and Roxanne. Kaisar appears after the storytelling and gets into an argument with Favaro. However, all four become distracted by Violet, who begins launching an attack on them.
The attack injures everyone but Jail. Concerned for his allies, Jail surrenders himself to Violet, who takes him back to the royal castle. Kaisar rescues Petra and he finds someone willing to nurse them both back to health. After this kind man takes them to the city, Petra and Kaisar decide to rescue Jail.
Kaisar steals clothes from a guard and disguises Petra as a corpse. Petra hides in a body bag which Kaisar presents to the two men guarding the entrance to the castle. The guards are convinced Petra is dead and lets Kaisar inside. Kaisar frees Petra from the bag and lets Petra lead him to the dungeons where Jail is being held.
The two successfully reach Jail's cell and free him. Petra and Jail cry heavily as they embrace each other. As the three make their way out they are confronted by Violet, but the timely appearance of Roxanne grants Kaisar a hostage and a means to get out of the castle. Masked soldiers intercept them at the port, but Favaro sails a ship into the pathway, knocking Roxanne and the soldiers into the sea.
At their hideout, Petra is shown tending to Jail who is asleep. An arrow with a note tied to it hits the wall and startles Petra, who goes to inform Favaro and Kaisar. After reading the note, the two men decide to confront Violet though Petra is hesitant to let them go at first. By morning, Jail is awake and decides to confront Violet as well. He attempts to sneak out but finds Favaro and Kaisar waiting for him on the road.
Petra spies on the trio and tearfully accepts that she will be waiting in the city for "Young Master" to return. She believes that once everything is settled, Jail will be happy and smile again.
Petra is seen briefly when the volcano appears to erupt. She is back at the royal castle and standing next to the king when Jail bids Favaro and Kaisar farewell, the trio having successfully defeated both Violet and Roxanne.