Patty Thompson is a Demon Weapon and the younger sister of Liz Thompson. Known as one of the "Demon Twin Guns", both her and her sister were known as the "Brooklyn Devils" and were petty thugs until being found by their now current Meister and Shinigami, Death the Kid. Over time, she reformed from her thieving and ruffian ways along with Liz and became Kid's weapon and later became DWMA students within the E.A.T Class. Patty acts and speaks like a young child, often using a singsong voice. She pronounces words like "hello" and "sorry", as a child would "hullo" and "sowwy", and seems to still be learning about simple things such as assigning animal noises to the right animal. This child-like disposition can lead to her coming across as nosy or insensitive. This lack of knowledge may be due to her growing up on the streets and presumably not having a formal education. Unlike her sister Liz, Patty enjoys the drama brought on by Kid's perfectionist attitude; though she does cheer him up when he gets down on himself about it. She seems naïve and simple-minded, seeming not to take life seriously. While Patty had these traits before moving to Death City, such simplemindedness was far more violent and nefarious. With time working at Deathbucks Café, Patty would spend her off-time building a dragon sculpture out of napkins and frightening Tsugumi Harudori with her ghost Halloween outfit. She also seems fascinated by the smallest details, such as children's alphabet books or a hair clip. She frequently laughs, even when something bad happens. On the few occasions when she loses her temper, her childlike personality is replaced by almost insane anger, as if her personality returns to how she behaved when a criminal in Brooklyn. Her demeanor can be so frightening that it scares Kid, even to the point of risking running through an asymmetric Tadpole Bomb minefield. When confronting some serious topics, and dangerous situations, Patty's childishly naïve personality is replaced with a more serious personality, suggesting that her bubbly personality may be a mask or merely how she wants to act.