He is the son of Evil Manta, who is a recurring villain in the series.
After reading all these raving reviews I ordered her one.
She shows that she hates being criticized in the film when she berates Undertow.
Celia reveled in watching Ariel's sister, Aquata, swimming for her life in a caged maze from a sea monster trying to eat her, all for public amusement and to blackmail Ariel.