Ursula appeared in the animated film The Little Mermaid, as a devious sea witch who tried to take over Atlantica through the king's daughter, Ariel. She granted Ariel the ability to transform into a human so that she could be with a man she loved, under the conditions that she was able to get the man to kiss her. In order to ensure Ariel's failure, Ursula set out as a human herself named Vanessa. She was able to get the trident from the king in exchange for Ariel's life, but was inevitably killed by Prince Eric using a small ship's mast. She was a recurring villain in The Little Mermaid's animated series.
Ursula was one of several villains who joined forces with the Heartless in the first Kingdom Hearts. She used the Heartless against Atlantica in order to gain control, similar to her role in the film. She used the trident to battle Sora, Donald, Goofy, and Ariel, but was defeated after numerous battles. She also appeared in Kingdom Hearts: Chain of Memories as a past enemy faced by Sora. In Kingdom Hearts II, Ursula appears once again, though it is unknown how she was able to return.