Pan is a Human-Saiyajin quarter-breed from Dragon Ball Z and Dragon Ball GT. She's the daughter of Gohan and granddaughter of Goku, making her the character with the most diluted Saiyan blood in the original series. Her name is a clever double-pun by Akira Toriyama—it references the Roman god Pan (fitting her mother Videl's mythology-based naming scheme) while also meaning "bread" in Japanese and Spanish, continuing her father's food-themed name.
In the original Japanese version, Yuko Minaguchi voiced Pan, while Elise Baughman handled the FUNimation dub and Caitlynne Medrek did the Blue Water Studios redub.
Pan barely shows up in the manga itself—just three chapters—so her character really gets fleshed out in the anime-only Dragon Ball GT. There she travels the galaxy as a young girl alongside her grandfather Goku and Trunks, the half-Saiyan son of Vegeta and Bulma. By the series finale, she's an elderly woman over 100 years old.
Her inability to transform into a Super Saiyan became a whole thing with the source materials. The Daizenshuu flat-out stated she couldn't do it due to her diluted heritage, but Dragon Ball GT's Perfect File books later contradicted this, suggesting she could achieve it with enough training. Toriyama himself explained the real reason: he couldn't figure out a logical design for a female Super Saiyan. The transformation's visual traits just skew masculine, and he didn't want to force it. Ironically, her grandson Goku Jr. ends up being a Super Saiyan anyway, which contradicts the whole "too little Saiyan blood" rule the Daizenshuu laid out.
Content compiled by AnimeList.moe from publicly available sources.