Marina Del Rey is the main antagonist of The Little Mermaid: Ariel's Beginning.
She is voiced by Sally Field.
The Little Mermaid: Ariel's Beginning
She is a mermaid and the governess of King Triton's seven daughters, in charge of enforcing Triton's distant and formal parenting style. She feels she has been stuck as the governess for too long, and her primary motivation in the film is to take over Sebastian's job as the King's attaché by any means necessary.
She temporarily succeeds after getting Sebastian, Flounder, and their entire secret music band sent to prison (music was forbidden from Atlantica at the time), but upon learning of the gang's escape with Ariel to find Triton's old music box (the only object that will get him to change his mind), Marina resolves to kill them all by sending her electric eels after them.
While the eels battle the gang, Marina takes on Sebastian, who outsmarts her every move and ultimately gets her trapped inside a coral spike. Marina does not give up, however, and still tries to kill Sebastian by crushing him. Ariel pushes Marina away, and she is sent to prison for her crimes.
Marina is extremely interested in clothing and fashion, and is the only merperson in the series who is seen wearing clothing over her fin to change its color and appearance.