Princess Mindy Neptune is the tritagonist of The SpongeBob SquarePants Movie and a supporting character in its tie-books and video games. She is the daughter of King Neptune and Queen Amphitrite and is Prince Triton's sister. She knows the names of all the sea creatures. It is also certain that King Neptune will crown her queen one day.
She later makes a surprise cameo appearance in "SpongeBob's Big Birthday Blowout”, which is also her series debut. Previously, she never appeared in the show because of a firewall between Nick and Paramount from 2004 to 2015 that prevented any elements from the movie (such as characters and locations) from being used in the show.
Mindy has light-green skin, dark-blue hair, wears round black glasses, a light-green tail, and a yellow hair bow. She wears a golden bracelet and also wears a pink midriff top with a red heart in the middle.
She is known to use "mermaid magic" to help others overcome their fears, but there really is not any mermaid magic; it is just fake. Mindy tries to get SpongeBob and Patrick to keep going when they give up their journey, so she convinces them that she has "mermaid magic" and uses it to "turn them into men" by pulling seaweed out of the ground and putting them on their noses, successfully helping them by tricking them into thinking that they are real mustaches. Dennis reveals the trick after SpongeBob and Patrick pass through the trench.
Mindy is considered by Patrick to be very beautiful and good-hearted and has a deep love for all the ocean-dwellers.
Unlike her father, she shows more compassion toward her father's subjects. This is best seen when she exonerated the Royal Crown Polisher for spending time in the dungeon since he was simply doing his job and criticizing her father for a harsh and unfair punishment. She also stated she has memorized the names of all the fish in the sea, something she stated was going to help her be queen.
She also encourages Patrick and SpongeBob to continue to Shell City, despite the others doubting them. She was even guilty that she lied to them that they became men, which caused them to run into danger with overconfidence but was happy they succeeded.
In the video game adaptation of the movie, Mindy reveals she actually does have mermaid magic, which she uses to get the Patty Wagon back in exchange for 50 Goofy Goober tokens.