Pan

Pan is a cute and tomboyishly beautiful little girl from the Dragonball franchise. She is a minor character introduced in the end of Dragon Ball Z and the main deuteragonist of Dragon Ball GT.

She is the daughter of Gohan and Videl, who married sometime after the Majin Buu Saga. She is the granddaughter of DB's ultimate hero Goku, his wife Chi-Chi, and the good-hearted yet greedy goofball glory-hound Mister Satan. She is the niece of Goten, though she tends to treat him more as a big brother. She regards the family of Bulma and Vegeta as family as well, and may sport a crush on Trunks. Her name derives from two traditions : Goku's family naming system, based on foods, and Videl's, based on mythological and religious tricksters. Like with Goten and Trunks and Bulla, it is unknown if she was born with a tail.

While her power level is formidable and should never be underestimated, she is also never shown to become a Super Saiyan. Akira Toriyama has said he struggled with what she would look like in that form, while fan speculation has placed Gohan's 'Mystic Saiyan' mode, which involved SSJ-like power without the physical transformation, as the cause for this. However, only a brief portion of her life is ever depicted in the series, and since her own descendants had this power, it remains possible she developed it later on.

Dragonball Z
Pan appeared briefly in the last few episodes of DBZ. She was only four years old at the time. Since ten years had passed since the defeat of Evil Buu, it seems she was born six years after that. She is shown to be utterly devoted to three things : Her grandfather, eating, and training, and at this time, she wore a miniature form of one of Goku's classic uniforms. Perhaps as a sign of maturity and perhaps as a sign of surrender to the realities of her Saiyan family, Chi-Chi no longer even tries to restrain her as she did Gohan.

Black Star Dragonball Saga
In the first saga Pan, along with Goku and Trunks, go into outer space to collect the black star dragon balls in order to make sure the earth doesn't explode. The trio go into many adventures and even met a mini-bot named Giru, which Pan befriended.

Baby Saga
In the second saga Pan, Trunks, and Goku land on a planet where robots rule the world. There they find a mutant machine known as Baby. They think they have killed him after Goku and Trunks blasted him, but unknown to them Baby still lives. All of them go back to earth where Baby infects the entire planet and is now under their control, that includes Pan's parents Gohan and Videl. After Goku transforms in a Super Saiyan 4, Pan, Gohan, Goten, and Trunks help him defeat Baby.

Super Android 17 Saga
In the third saga, Pan helps out the Z-Fighters fight Android 17 but is ultimately defeated by the android. After Goku and Android 18 killed Super 17, the entire gang summon Shenron but an evil version of Shenron.

Shadow Dragon Saga
In the final saga, Pan helps SSJ4 Goku and SSJ4 Vegeta defeat Omega Shenron. Vegeta then tells Pan to take care of Goku's cloths as that might be the only thing left to remember him.

DBGT Special
100 years later Pan, now 114 years old, trains her grandson, Goku Jr., into making him the strongest warrior on the galaxy just like his great, great grandfather Goku.

Trivia

 * Pan is the only main female character of Dragon Ball GT, Bulma, Chi-Chi, Android 18, and her mother Videl all serve as secondary characters and Bulla & Marron serve as tertiary characters.
 * However Android 18 was the tritagonist of the Super 17 saga and Bulma (under Baby's control) was the secondary antagonist of the Baby saga.