She is portrayed as the tactician and self-proclaimed leader of the Powerpuff Girls, alongside her sisters Bubbles and Buttercup, with whom she fights crime in the city of Townsville.

[12] Cavadini speculated that this could have been a matter of age discrimination, given that Cartoon Network wanted the voice cast to do appearances in person, thus choosing to represent the girls through younger actresses.

[14] However, at the 2017 New York Comic Con, Strong stated that she had no ill will towards the new cast and had given the show her blessing,[15] as did Cavadini in 2018, by saying that she and Leighton were friends on Facebook.

In the 1998 series, Blossom (voiced by Cathy Cavadini) is the "commander and leader" of the Powerpuff Girls and a regular student at Pokey Oaks kindergarten.

[21] Blossom is not exempt from committing certain reprehensible acts, however in the few instances she does something wrong (such as stealing golf clubs to give the Professor for Father's Day)[22] she is quick to own up to her wrongdoing.

She is a 13-year-old middle schooler and a member of the Powerpuff Girls Z, where she is no longer a creation of Professor Utonium and her link to Bubbles and Buttercup is rather circumstantial.

Her unique abilities are ice breath, genius-level intelligence, microscopic vision, natural leadership skills, and intuitive aptitude.

[36] As for her abilities as a leader, Blossom always shows determination, has a sense of danger, is quick to action and often calls out names for attack formations during battles.

[38] In the book America Toons In: A History of Television Animation (2014), author David Perlmutter describes Blossom from the 1998 series as a "strong-willed figure who is equal parts diplomat, intellectual, general and politician".

However, this also plays as a flaw in her overall depiction as a seemingly superior member of the Powerpuff Girls, since she often displays her "tactless arrogance toward friends and foes alike", to which Perlmutter adds: "But McCracken and company never allow her to go too far.

"[40]: 20–21  However, when her hair gets butchered in the episode "The Mane Event" (2000), which makes her subject of much ridicule by the people of Townsville, Blossom loses her confidence and chooses isolation over fighting a monster with her sisters.

"[40]: 24–25  She adds, however, that "Although one meaning of [the episode] could be that appearance should be subordinate to behavior, a resistant reading of 'The Mane Event' suggests that looking girlish is no choice, but rather an imperative of girl power.

"[40]: 24–25 In a critical essay on the 1998 series, Argentinian author Márgara Averbach stated that there appear to be ethnic implications in Blossom's design, describing her as "the redhead, descendant of northern Europeans" (deeming it part of a "very traditional classification of human characteristics") and observing that her appearances on screen usually obey a hierarchy among her sisters (when Blossom is in the middle, closer to the upper part of the screen, meaning that she guides the other two).

[41]: 60, 64  Despite this, Craig McCracken argued that he designed the girls while simply looking for "a little diversity and balance" in the drawing, not knowing that these characters would transcend his initial intent.