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. Likewise, her personality is quite similar to Ariel from Disney's The Little Mermaid.
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.