Mindy is King Neptune's mermaid daughter, introduced in The SpongeBob SquarePants Movie. She was designed by one of the show's main writers and artists, Sherm Cohen, who confirmed that Mindy is 13–14 years old.
In the movie, Mindy is King Neptune's daughter. When Mr. Krabs is frozen by King Neptune, Mindy, due to her soft heart, tries to help SpongeBob and Patrick find the king's crown so that he will let Mr. Krabs live. She contacts SpongeBob and Patrick by a special connection. Mindy gives SpongeBob and Patrick a magical bag of winds to help them on their journey. She was voiced by Scarlett Johansson.
Mindy is usually portrayed as being very kind, as she helps SpongeBob and Patrick in their journey to Shell City. She detests her father a lot. Additionally, she is very attractive, seeing that Patrick is always dumbstruck by her beauty. She is the only one that believes in SpongeBob and Patrick, even if they are "just kids".
 Royalty Connection
Mindy, since she is the daughter of King Neptune, is a mermaid. In the movie, she revealed that one day, she will be the queen of the sea. She knows the names of all the creatures in the sea, in preparation.
Mindy is a mermaid who has light-green skin, short dark blue hair and a turquoise tail. She has freckles above her nose. She wears round black glasses, a yellow hair bow, a golden bracelet and a purplish-pink crop-top with puffy sleeves, purple edges on the bottom of the sleeves and a pink heart in the middle.