Lady Rainicorn (voiced by Niki Yang in the TV series,[REF] Dee Bradley Baker in the original pilot short[REF]) is a Rainicorn, a half-rainbow half-unicorn creature, as well as Jake's girlfriend and Princess Bubblegum's companion [REF].
Betty Grof (voiced by Lena Dunham[REF], later by Felicia Day[REF]) is the former fiancée of Simon "Ice King" Petrikov-turned-recurring antagonist.