Black Adder is a pale silver Pegasus pony with dragon-like wings and red eyes. She had black hair with pinkish-plum streaks, held back by a blue hair band. Her cutie mark is a black snake with yellow eyes.
She has long white fangs, and they're known to have potent venom.
Black Adder was born in Canterlot, daughter of Quetzalcoatl and Black Bat. Like her parents, she was mainly nocturnal and liked to terrorize the people living nearby. Soon, Quetzalcoatl passed away of unknown causes, and Black Adder was told by her mother to move to her sister's house. There, Black Adder met her four cousins: Holly Wreath, Moon Drop, Cattail, and Poison Ivy. She was fine with her aunt Star Gazer, as well as Holly, Cattail, and Ivy, but she distinctly hated Moon Drop for some reason.
Several weeks later, she went to Bunsen Burner's class, spending recess time to torment Sour Ball. It was until Sour Ball hit her head that she would do this. Afterwards, she grew distant with her aunt's family, and went back to Canterlot to find her mother, only to discover she had left. Filled with anger, she went to Celestia's royal garden to work off some steam. Sugarcake attempted to stop her, causing an argument and releasing Discord. Soon after that, she found she was the element of Fear; able to conjure up pony's worst nightmares.