Movie Minute - Who is Morgana? The Little Mermaid II: Return to the Sea

Morgana is the younger sister of the wicked sea witch named Ursula, whose place she takes as the main antagonist of Disney's 2000 direct-to-video animated sequel film The Little Mermaid II: Return to the Sea, the sequel to Disney's 28th full-length animated feature film The Little Mermaid. Like her sister, she is a cecaelia, a species of water-dwelling (near mermaid-like creatures) but with the bottom half of an octopus and appears in the second Little Mermaid movie together with her minions Undertow, Cloak and, Dagger. She is Melody's arch-nemesis.

Morgana is very skinny, closer to a squid than an octopus. She is younger than her sister, and her skin is light green. Morgana's octopus arms are green instead of purple like Ursula's. Also, her bottom portion of her body resembles a black gown. She can release ink from her tentacles.

When Morgana was young, she was liked less than Ursula by her mother. Morgana was criticized for her jealousy of Ursula. Their mother soon died as revealed by Morgana when she, herself, usurped King Triton's throne, becoming queen herself. A picture of Ursula and Morgana's mother was seen in the deleted scene "Gonna Get My Wish". It is less likely she was banished from King Triton's kingdom like her sister Ursula was.

The party celebrating Melody's birth is interrupted by Morgana attempting to prove her superiority over Ursula. She attempts to feed Melody to Undertow but fails when Prince Eric and Ariel rescue Melody. So, Morgana and her two manta rays, Cloak and Dagger, leave in a huge funnel.

Morgana, Undertow, Cloak, and Dagger live in an iceberg lair. Morgana is trying several attempts to change Undertow back into a shark, but all fail. Morgana believes that Trident is too powerful for her. It is revealed that Morgana does not like being criticized because her mother criticizes her and tell her she should be more like Ursula. It is also revealed that their mother favored Ursula more than Morgana. Morgana and Undertow argue about whose fault was what about hiding in the lair. Suddenly, Morgana's orb shines and shows her Melody discovering her grandfather's locket, inciting Morgana to use Melody to her advantage.

Like her older sister, Morgana is oppressive, cruel, sarcastic and manipulative. She shows that she hates being criticized in the film when she berates Undertow. She wants to steal the trident to prove her superiority over her sister. However, she lacks her sister's deviousness and gets easily upset when she is told that she is not as good as her when using potions, as shown when Morgana fails all attempts to turn Undertow back into a shark, much to her embarrassment. Morgana is shown to have twisted sense of humor, such as at the beginning when she grabbed Eric's advisor, Grimsby and said: "Now, is that fair Gramps, I asked you.". She tickled Grimsby's chin with her fingers and with a nice smile. She then said, "But then whoever said we had to play fair?". Though Morgana's personality is different, she does have the same objective as Ursula. Many people think that she was less interesting than Ursula. However, at the same time managed to hang on to the trident longer than her.
Although she ultimately desired vengeance against Ariel and Eric for their role in Ursula's death, she also simultaneously disliked and envied her sister due to her neglect from her mother, as the latter favored Ursula far more. This dislike is shown when she is shown to have a picture of her late sister where instead of treasuring said item, she fired darts at it out of spite when remembering their mother favored her. Also in a deleted song, she sung about how her sister "blew it!" and lost the trident to Ariel which led to her defeat before stating it was her time to take power.
Source: DisneyWikia