Undyne (Undertale Film)

Undyne is a character in the Undertale 2025 film. She is a fish-like monster that leads the Royal Guard. Clad in her full suit of armor, she pursues Frisk through the entirety of Waterfall and is frequently evaded or inadvertently thwarted by Monster Kid.

Appearance
Undyne is a piscine, anthropomorphic monster. She has blue scales and a long red ponytail. She has red and blue fins on the sides of her head, and a pair of sharp, yellow, protruding teeth. She wears a red eye shadow and has an eyepatch on her left eye. She also wears a black tank top and jeans, but debuts in armor varying in light and dark shades of gray. Her eyes have black vertical pupils and yellow sclera. Undyne has no nose.

During the date with Alphys, Undyne wears a white turtleneck under a black leather jacket, a scarf around her neck, pants, lipstick, a light-colored eye patch, and lets some of her hair down.

Personality
Undyne is passionate, and aggressive, about everything that she does. She acts quickly on her ideas and is steadfast in her beliefs. Though she wants to defeat Frisk, she also tries to be fair and offers an explanation of how Green Souls works. Asgore taught her the value of pacifism, which is why Undyne sees Frisk as "a wimpy loser with a big heart." When Frisk first encounters her, she fights to further Asgore's plan of collecting seven human souls but, if Frisk shows mercy, Undyne just as quickly defends them from Asgore.

She loves to help others and mentors Shyren and Papyrus in various skills. Undyne dislikes puzzles, and enjoys anime, an affinity she shares with her romantic interest, Alphys. Since Alphys told Undyne that anime is actually human history, Undyne regards human history as exciting and cool. Out of all encountered monsters, Undyne possesses the most determination. However, she knows very well that Frisk's determination is much greater than hers, which after befriending her, she commends Frisk for.

Abilities
Undyne has the power to summon magic spears from seemingly nowhere, which can attack any person she aims them at. Normal spears are light blue and aim straight for their target, while other spears are yellow, and go at their target from behind, before flipping into the opposite direction. She also has the power to turn human souls green, making them unable to move their legs an inch from where they stand.