Mariah is a villainess from the third arc of JoJo's Bizarre Adventure, Stardust Crusaders.
Mariah is one of the mercenaries hired by Dio Brando to assassinate Jotaro Kujo and his friends, though she serves Dio mostly because she finds him attractive. She initially attacks Joseph Joestar, using her Stand to create a outlet over a rock which he touches out of curiosity. This places a curse on him which turns him into a living magnet, attracting metal objects to himself.
Joseph finds something is wrong when metallic objects start flying into his direction, so he tries leaving the hotel he was on to seek help of his friend, but he ends trapped on a moving staircase. Mariah, who was just in front of him, uses the cords on her dress to trap him further, but as he is about to be crushed Avdol saves him by stopping the staircase, though he too touches an outlet and gets magnetized.
The two start pursuing Mariah, but the magnetism intensifies as the two start attracting each other. Mariah attracts them to a railroad where they are almost killed by a train, though Avdol saves them by burning a portion of the track. They eventually manage to separate from each other and get into separate ways, cornering Mariah in a street. However their magnetism gets stronger, starting to attract large metal pieces and even cars. As the two start to get overwhelmed, Mariah uses knifes to cut the electric wires of the street, which also gets attracted to them.
Joseph begs her to dispel their curse, to which Mariah replies that she would like to do it as she finds Joseph attractive, but in her eyes Dio was much more attractive than him. At this point both Joseph and Avdol stop struggling and get attracted into each other, and Mariah ends up crushed between the two, thus deactivating her Stand. She is sent to the hospital with all bones in her body fractured. Later it is said that she is unable to recover fully and must prematurely retire.
Mariah's Stand, Bast, manifests as a power outlet which she can place wherever she wants. Anyone who touches the outlet becomes magnetized, attracting metal objects to himself. The magnetism intensifies with time, but Mariah must keep relatively close to the victim.