Due to her actions and role, she is a supporting antagonist in the Wano Country Arc.
Black Maria is a youthful woman of incredible size by human standards, at 8.2 meters tall being similarly large as Kaido himself. Her long blonde hair is styled like a geisha's, with two swords notably being part of its arrangement. Her eyes are sky blue, and a strand of hair tends to dangle in front of her left eye.
She has a pair of long, slightly curved red horns atop her head, wears prominent lipstick, and carries a long smoking pipe. She wears a low-cut dark kimono that leaves her right shoulder exposed and an obi around her waist, both with floral patterns.  She has the kanji 女難 (kanji meaning "woman trouble"?) tattooed on her back. In her Zoan form, her spider forelimbs each bear a personalized Jolly Roger, indicating she may have them tattooed on her original body.
Black Maria is a flirtatious, courtesan-like figure who takes a laid-back approach to her missions and duties as one of the Tobiroppo. When assigned to fight or hunt for a target, Black Maria instead prefers to stay back from the action and enjoy the company of her captain or play music with her subordinates, taking refuge in safe locations away from all the strife while letting her peers deal with the problems themselves. She also has a soft spot for children, taking pity on Momonosuke after he got brutalized by Kanjuro and tending to his injuries before Orochi took him away.
That being said, Black Maria can be just as violent and sadistic as the rest of the Beasts Pirates, if not moreso. In stark contrast to her usual playful attitude seen during the Golden Kagura, Black Maria is a ruthless torturer when actually performing her job as a pirate, not holding back her punches for the sake of the crew's objectives. Even if the victim actually decides to cooperate with her, Black Maria may not honor her word and just keep them trapped under her power. When asked about her methods to keep Robin in line should the Beasts Pirates manage to capture her, Black Maria simply stated that she would mutilate the Straw Hat to the point of helplessness, then kill and discard her corpse after her purpose to read Kaido's Poneglyphs was fulfilled.
Black Maria enjoys keeping captive men as "pets" for her to play with (particularly those with rebellious personalities). Through torture methods, she forcefully implants obedience and devotion inside the heads of her victims until they become unable to say anything else but declarations of love and worship towards her, effectively turning herself into their subject of adoration. Black Maria is extremely possessive of those men and will not tolerate any attempts of "infidelity" from them, resorting to further violent discipline if necessary.
Abilities and Powers
As one of the Tobiroppo, Black Maria holds great authority in the Beast Pirates, with only Kaido and the All-Stars ranking above her. As the owner of the Woman Trouble, she oversees the goings-on in it.
Though Black Maria's combat ability has not yet been witnessed, as one of the six strongest Shinuchi, she can be assumed to be very powerful, potentially worth challenging the All-Stars for their position.
Black Maria has shown herself to be a crafty strategist, having collaborated with her subordinates to come up with an ingenious trap to subdue Sanji, one of the Straw Hat Pirates' strongest members, by taking advantage of his obsessive chivalry, having Sarahebi feign being sexually harassed while she used her spider web to trap Sanji, allowing Sarahebi and another Beasts Pirates member to effortlessly subdue Sanji.
Black Maria ate the Kumo Kumo no Mi, Model: Rosamygale Grauvogeli, an Ancient Zoan-type Devil Fruit that allows her to transform into a full Rosamygale grauvogeli — a prehistoric, carnivorous spider — as well as into a human-spider hybrid at will. Her hybrid form has a centaur-like body; whether this is her default hybrid form or a conscious choice she made is currently unknown.
She has several spider abilities, including the ability to walk on walls and ceilings with her spider legs. She is also able to shoot extremely sticky webs from her body that she can use to trap and bind her opponents. She claims that anyone trapped in them will never be able to get loose. Her webs can even be made into an intricate series of traps, so that no matter where someone steps, they will get captured.
Black Maria used a pair of knuckledusters in order to physically torture Sanji after capturing him. Her original intent was to force him to shout for Nico Robin to come save his life, although she intended to continue punching Sanji even after he did so, as part of the disciplinary measure she reserves for her "pets".
Once Robin and Brook infiltrated her banquet hall and freed Sanji, Black Maria picked up a polearm, at the end of which was a figure of a wanyudo, a flaming wagon wheel-like demon with a mans face on the side. The capabilities of this weapon are currently unknown, as is Black Maria's proficiency with it.
Wano Country Arc
Black Maria and the other Tobiroppo members arrived at Onigashima during the Fire Festival. Kaido had them brought into his fortress, and as they waited to meet with him, Black Maria enjoyed watching Ulti become confrontational with anyone who annoyed her. However, she and the other Tobiroppo members became shocked when Ulti spoke rudely about Kaido as she questioned the purpose of their meeting. As the group came before Kaido, he gave the six the mission of finding his son Yamato, saying he would let them battle one of the All-Stars for their post if they succeeded, with Black Maria noting that such a mission would be difficult.
Instead of searching for Yamato like her comrades, Black Maria decided to stay with Kaido and Orochi. After Kanjuro arrived with the badly beaten Momonosuke, Black Maria tended to the young boy's injuries and let him rest his head on her lap. However, he was soon seized by Orochi, who revealed his plan to have Momonosuke crucified, much to the discomfort of Black Maria.
As the Ninja-Pirate-Mink-Samurai Alliance waged war on Onigashima, Black Maria received a call from King informing the Tobiroppo that the challenge for an opportunity to fight the All-Stars was cancelled, and that they were to stop the enemy alliance from getting to the roof of the dome, where Kaido was fighting the Nine Red Scabbards. Rather than engage the invaders, Black Maria and her subordinates retreated to the castle's tatami room, where they intended to wait out the battle. To help pass the time, Black Maria played her shamisen and sang a song about two lovers meeting beneath the moonlight.
She later encountered Sanji after two of her subordinates lured him into a trap and captured him. Brought before the Tobiroppo member, Sanji exchanged banter with Black Maria, who admitted that she had a soft spot for "boys with rough edges" like Sanji. Although initially insulted by Black Maria referring to him as a "boy", Sanji soon became smitten with her. When Sanji tried running away, Black Maria activated her spider hybrid transformation and chased after him, saying she wanted him to stay as her pet. Although Sanji was able to fend off Black Maria's male subordinates, his refusal to hit her or her female subordinates allowed Black Maria to trap him once again. She then told him to call out to Nico Robin through a special mask that her subordinate Caimanlady wore, saying it would broadcast his voice through the whole castle and lead Robin right to them. Before she could use the mask, Black Maria received a call from King that the wounded Nine Red Scabbards had been spotted in the Treasure Repository on the castle's second floor. Since that room was not too far away from her, Black Maria volunteered to head there to kill them afterwards.
When Caimanlady confirmed that she was ready to broadcast Sanji's voice across the island, Black Maria continued trying to force Sanji to call for Robin, revealing she had laid multiple layers of her adhesive thread at the entrance and on the floor to trap her. When he still refused, Black Maria put on brass knuckles and used them to pummel Sanji until he finally called for Robin. After doing so, he demanded she let him loose like she said she would, but Black Maria revealed that she intended to keep Sanji as her pet, similar to other men she had taken captive. When Sanji scoffed at her, Black Maria prepared to assault him again, but Robin, having bypassed the traps, arrived and knocked Black Maria away with her Devil Fruit powers, while Brook freed Sanji from the webs. Black Maria was then called by Jack, who was on his way to kill the Scabbards himself, ordering her to stay where she was and not interfere. Although insulted, Black Maria accepted his decision and prepared to fight Robin and Brook instead.
- Black Maria is likely named after the British card game of the same name, fitting with the card game-themed names of the Shinuchi. "Black Maria" is also a nickname for the Queen of Spades card.
- Black Maria's favorite food is mitarashi dango.
- Black Maria's name may also be a nod to the Black Widow, a highly poisonous spider whose females are known to eat their mates.