Wendy debuted as a nameless background character in Trey Parker and Matt Stone's 1995 college short film The Spirit of Christmas, and made her first appearance on television when South Park initially premiered on Comedy Central on August 13, 1997, with the episode "Cartman Gets an Anal Probe".

In the 1995 short The Spirit of Christmas and South Park's debut episode, "Cartman Gets an Anal Probe", Wendy is composed of construction paper and animated through the use of stop motion.

Starting with "Weight Gain 4000" onwards, she is animated via computer software, though her appearance is portrayed to give the impression that the show still uses its construction paper technique.

[1][2] Wendy is usually depicted wearing winter attire consisting of a light purple jacket, yellow pants, navy blue gloves/mittens, and a pink beret.

While Mary Kay Bergman, Eliza Schneider and Mona Marshall originally voiced Wendy without any computer manipulation, April Stewart now speaks within her normal vocal range while adding a childlike inflection.

Despite the problematic elements of their relationship, Stan is still shown to have feelings for Wendy whenever the two break up; in the episode "Raisins", he is left devastated for weeks after she dumps him in favor of Tolkien Black and joins an alliance of goth children as a result.

In the video game South Park: The Fractured but Whole, Wendy and Stan are shown together as their respective superhero alter egos, Call Girl and Toolshed, with flirtatious dialogue.

"[8] PasteMagazine ranked her at #12 on a list entitled "The Top 20 Best South Park Characters" and praised her for her oppositions of the politically incorrect portrayal of society.