Betty Grof

 was a human woman in "Adventure time", revealed to have once been the fiancée of a man named Simon Petrikov, who would much later become the Ice King. She and Simon had a very committed relationship until he obtained an enchanted crown, which gradually began to alter his mind and body. When Simon put on the crown for the first time, something he did terrified Betty and caused her to leave. Simon never saw her again, and he records on video his desperate wish to regain his sanity so that she might one day return to him.

Appearance
Betty is an adult woman appearing to have pinkish skin and dark red, or light brown hair. In a picture on Simon Petrikov's wall, Betty is seen wearing glasses and a green turtle neck. In another picture, Betty is wearing a lab coat. This might suggest that she was in a field of study, such as science or medicine.

Trivia

 * Simon referred to Betty as his princess while he still possessed some of his sanity.
 * Adam Muto stated that the figure in the picture with Simon and Betty is "some sort of cryptid." A cryptid is a creature that has been sighted before but whose existence is unconfirmed by science.
 * Pendleton Ward and Rebecca Sugar have stated specifically that Betty and Doctor Princess are not the same person.