Jefferson is a supporting character in Once Upon a Time. Originally, he was a poor fungus merchant and single father to Grace.
When he became trapped on the other side of the looking glass, he kept trying to make another magic hat to take him back, he made thousands upon thousands but none worked, thus he became the Mad Hatter.
In Storybrooke, after the curse, Jefferson still remembers who he is and spends his time watching his daughter, Grace, now Paige, through a telescope, happy with another family.
Origin: Enchanted Forest
Also known as: Mad Hatter
The Evil Queen
Portrayed By: Sebastian Stan
First Appearance: "Hat Trick"
Last Appearance: "The Doctor"