Peter's short-tempered and unmannerly; he's prone to violence and often makes rude, sarcastic remarks. He harbors no qualms about killing other individuals or even striking / threatening other members of the circus. Despite his tendency to anger easily, he's capable of making quick decisions, such as when he abandons attacking Finnian to take out a more serious threat. He's perceptive and keen, as demonstrated by his ability to swiftly deduce the reason for the Phantomhive's large gun collection. Peter may bear some ill will toward Doll, as he frequently belittles her as someone much too childish. He may also not be very fond of Snake, as he has threatened to take his life if he fails to perform well. However, he cares deeply about Wendy, as he's almost always by her side, and tends to her injured ankle. He also seems to respect Jumbo, as he listens to his advice and is greatly distressed when the latter is killed. Peter, originating from the East End, speaks in Cockney English.Peter grew up in an alley in East End, referred to as a gutter, with the other first-string circus members, (minus Snake). Joker stated that they came together because they were each defective in a way. In Peter's and Wendy's case, they're trapped in children's bodies. For this reason, even though they seem to be the youngest of the circus members, they may actually be significantly older; this is implied when Peter reprimands Doll for being a child, despite appearing to be younger than her. Ten years ago, Doll rushed up to Joker one day with a tooth in her hand. She gleefully exclaimed that it fell out, believing that she'd later get a coin from the Tooth Fairy and promised them that she'd buy them all bread afterwards. Peter began to retort that the Tooth Fairy didn't actually exist but was prevented from doing so by Jumbo. When he angrily questioned why he didn't allow him to speak, Jumbo replied that it was hard to break the truth to her whilst seeing her smile like that. Joker agreed, additionally musing that gap teeth are too cute to be legal. Beast commented that if Doll didn't get her coin the next morning, she'd be extremely upset, to which Joker decided that he should attempt to earn something. Joker opposed Peter's idea of stealing, stating that he had a feeling it would be wrong to use stolen money "this time." In resignation, Peter frustratedly exclaimed that he hated kids but decided to come along with him, stating that if they all go, they might be able to earn something. Peter, Joker, Beast, Dagger, 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. However, in the belief that the Tooth Fairy would give her more coins, Doll later attempted to take out more teeth that were not wobbly, which Peter found troublesome. As thieves, they were unsuccessful and barely managed to survive. At some point, Baron Kelvin found them in the alley and adopted them. After living at Renbourn Workhouse for some time, they decided to start a circus, and Peter and Wendy formed the trapeze act.