Beast's a very domineering, aggressive, and ill-tempered individual; when irritated, she's quick to lash out and resort to violence. Furthermore, while she has a close bond with the other first-string members, Beast particularly loves and cares deeply for Joker, even though she's fully aware that he'll never return her affection. Unlike the other first-string members, Beast does not seem to hold Kelvin in the same high regard. She's also more willing to abandon the other children back at the Renbourn Workhouse, as indicated when she asked Joker if they can run away from Kelvin. Beast, who originates from the East End, speaks in Cockney English.Beast was born without a left leg, as Mally to a scullery maid named Amelia. She grew up in an alley in the East End, referred to as a gutter with the other first-string circus members (except Snake). Joker stated that they came together because they were each defective in a way. In Beast's case, she's been missing her left leg since birth. Ten years ago, Doll rushed up to Joker one day with a tooth in her hand. She gleefully exclaimed that it fell out and promised she'd buy them all bread later, believing that she'd later get a coin from the Tooth Fairy. However, she was oblivious to the fact that it didn't actually exist. Beast commented that if Doll didn't get her coin next morning, she would be extremely upset, to which Joker decided that he should attempt to earn something. Beast, Joker, Dagger, Peter, Wendy, and Jumbo then proceeded to work on manual chores earnestly all night long in order to earn a single coin for Doll. They were relieved to see they made it on time as they placed it beside her whilst she was sleeping. The next morning, an oblivious Doll showed off her coin to them, stating how happy she was that they could eat bread with it and an exhausted but happy Beast smiled along with her. However, in the belief that the Tooth Fairy would give her more coins, Doll later attempted to take out more teeth that weren't wobbly, to the dismay of the others. As thieves, they were unsuccessful and barely managed to survive. At some point, Baron Kelvin found them in the alley and adopted them. While there, Beast seemed to have developed her crush on Joker, as she was touched by his offer to carry her on his back if he still had both arms, and was very glad to be in his presence. After living at Renbourn Workhouse for some time, they decided to start a circus and Joker gave her the stage name "Beast," which she initially was not excited about.