Toast Princess is the sister of Breakfast Princess. Both often attend official Princess meetings, and are often harassed by the Ice King.
Breakfast Princess and Toast Princess are both created by Pendleton Ward. Breakfast Princess also owes much of her creation to Cole Sanchez who developed and gave the character her current look. Pendleton Ward's original now defunct design for Breakfast Princess would eventually be later used for Toast Princess design and look. Both characters make their first comic book appearance in Boom! Studios, Adventure Time #3 comic released in 2012.