Jenny Sanderson
Jenny is the daughter of Mr. and Mrs. Sanderson and believes she was turned into a frog by the evil Frog Wizard (who doesn't actually exist).
She spends all her time with a frog hat, pretending to be a frog and communicating in 'ribbits. She pretends that only if she is given ten Frog Rings, she will be turned back to normal. But when Chibi-Robo gives her all ten Frog Rings, she'll just take her frog hat off until Chibi-Robo leaves the area again. Then she'll put the hat back on and say she's cursed again.