The Powerpuff Girls were created by Professor Utonium in an attempt to create the "perfect little girl" using a mixture of "sugar, spice, and everything nice" (shown in respective fields of light blue, light green, and pink). However, he accidentally spilled a mysterious substance called "Chemical X" into the mixture, creating, instead of the "perfect little girl", three girls (each possessing one of the above elements dominating her personality), and granting all three superpowers including flight, super strength, super speed, near invulnerability, x-ray vision, super senses, heat vision, energy projection, invisibility, and control over lightning. In the original pilot, the accidental substance was a can of "Whoopass", which was replaced by "Chemical X" in the aired version.
The three girls all have oval-shaped heads, abnormally large eyes (inspired by Margaret Keane's art), stubby arms and legs, and lack noses, ears, fingers, necks, and flat feet with toes (McCracken preferred them to look more symbolic of actual girls rather than going for a "realistic" look, meaning fewer body parts were needed). They wear dresses that match the colors of their eyes with black stripes, as well as white tights and black Mary Janes. The closing theme to the cartoon offers a nutshell description of the three Powerpuff Girls' personalities: Blossom, commander and the leader. Bubbles, she is the joy and the laughter. Buttercup, she is the toughest fighter.
Blossom (voiced by Cathy Cavadini) is the tactician and self-proclaimed leader of the Powerpuff Girls. Her personality ingredient is "everything nice", her signature color is pink, and she has long red hair with a red bow. She was named for having spoken freely and honestly to the Professor shortly after her creation as shown in the Powerpuff Girls Movie. She is often seen as the most level-headed, and composed member of the group and also strong and determined. Her unique power is freezing objects with her breath as seen in the episode "Ice Sore".
Bubbles (voiced by Tara Strong in the series and by Kath Soucie in the What a Cartoon! episodes) is the cute and sensitive one. Her personality ingredient is sugar, her signature color is blue, and she has short blonde hair in two pigtails. Bubbles is seen as kind and very sweet but she is also capable of extreme rage and can fight monsters just as well as her sisters can. Her best friend is a stuffed octopus doll she calls "Octi", and she also loves animals. She exhibits the ability to both understand multiple languages and communicate with various animals (squirrels, cats, monsters), and her unique power is emitting supersonic waves with her voice.
Buttercup (voiced by E. G. Daily) is the toughest of the three. Her personality ingredient is spice, her signature color is green, and she has short black hair in a flip. She is a tomboy who loves to get dirty, fights hard and plays rough; she does not plan and is all action. Buttercup is the only Powerpuff Girl without a unique super power (aside from being able to curl her tongue as shown in the episode "Nuthin' Special"). McCracken originally wanted to name the character "Bud" until a friend suggested the name Buttercup.