Ursula is a part-octopus sea witch who "helps" unfortunate merfolk to achieve her own goals. Ursula frequently turns them into polyps and imprisons them. Her appearance is of an obese purple-skinned, white-haired female human with a facial mole, but from the waist down she has six black tentacles.
When Ursula first appears in the film, she states through monologue that she once lived in the royal palace of King Triton. She was banished from Atlantica due to previously trying to attack and seize the throne, and made her home in the remains of a leviathan. Ursula commands her minions, the twin moray eels Flotsam and Jetsam, to watch Triton's youngest daughter Ariel, who might be "the key to Triton's undoing". Ursula forms her plan to seize power around Ariel's forbidden love for the human Prince Eric. Flotsam and Jetsam persuade Ariel to go to Ursula's lair, claiming that the sea witch is the only one who can solve her problem. Via the song "Poor Unfortunate Souls", Ursula proposes a deal in which she will turn Ariel into a human for three days. If Ariel receives the "kiss of true love" from Prince Eric before sunset on the third day, her transformation will be permanent. However, if Ariel fails, she will turn back into a mermaid and be bound to Ursula forever. The price of transformation is Ariel's voice. Ariel signs a magical contract and Ursula takes her voice, and then transforms Ariel into a mute human.
When Ariel comes "too close" to succeeding, an enraged Ursula decides to sabotage the bargain and takes the form of a beautiful human woman named "Vanessa". Ursula uses Ariel's voice to hypnotize Eric into marrying Vanessa at dusk on the third day. Shortly before the wedding, Scuttle discovers that "Vanessa" is really Ursula in disguise and hurries to tell Ariel, and then helps to ruin the wedding. Complete mayhem ensues, and Scuttle destroys Ursula's necklace, restoring Ariel's voice to its original owner. Ursula's control over Eric breaks, and he reunites with Ariel. However, the sun sets just before Ariel and Eric can kiss, and Ariel reverts back to her mermaid form. Ursula, transforming back into her original form, claims Ariel and drags her back into the sea. Ursula is quickly confronted by Triton who demands that she release Ariel, but the tables turn when Ursula reveals that the contract Ariel signed is unbreakable. Ursula offers to let Triton take Ariel's place in the contract, setting Ariel free, but in exchange Triton must forfeit his power. Triton agrees and is transformed into a polyp. Ursula takes the crown and magical trident, claiming herself as the new ruler of the seas. Meanwhile, Prince Eric decides to go rescue Ariel and fight Ursula. A small battle ensues undersea, culminating with Ursula accidentally disintegrating Flotsam and Jetsam with an energy bolt from the trident. After mourning for her pet eels, an enraged Ursula grows to gigantic proportions and begins creating a massive oceanic storm and whirlpool, which brings up several submerged ships from the depths. Eric manages to board one of these ships. In order to ensure that there are no other heirs to the throne, Ursula traps Ariel inside a whirlpool she created. Ursula then tries to execute the mermaid princess with blasts from the trident. Ariel just barely manages to survive each blast. Ursula then raises the trident and prepares an unavoidable, fatal blast for Ariel. The princess gapes in horror, certain of her doom. Just before Ariel's execution can be carried out, Ursula is defeated by Eric, who drives the sunken ship's broken mast into her abdomen, and she sinks into the ocean with the ship, while Eric barely managed to escape. With Ursula gone, her evil spells also cease to function; the polyps turn back into merpeople and escape from Ursula's hideout.
Ursula appears as a occasional antagonist in four episodes of The Little Mermaid prequel television series: "Against the Tide", "Tail of Two Crabs", "Heroes" and "Ariel's Treasures". In all four episodes, she executes various plans to antagonize King Triton and take over Atlantica, but all fail. In the first two episodes, interaction between Ariel and Ursula is kept at a minimum, but in the later ones, Ariel and Ursula face each other more directly. Ursula does not appear in the direct-to-DVD film The Little Mermaid II: Return to the Sea, but she is mentioned many times, mostly by her sister Morgana and is seen as a picture with a nice face. In the family portrait during the cut song "Gonna Get My Wish", Ursula was also depicted with Teal skin similar to Morgana.
Role in UltimaEditUrsula returns in Ultima to serve as one of the Organization's high ranking sorceresses in the Sorcerers Society. Her various magic spells and control over the Octopin Army make her a valuable asset to Maleficent's forces.
Ursula currently has control over a private regiment of Gesomon and Underwater Heartless that serve her commands in battles taking place under the sea.