Thundarr the Barbarian (1980)

S1E6 Attack of the Amazon Women

Thundarr, Princess Ariel, and Ookla arrive to help a group of amphibious Amazons, led by the overthrown Queen Diona. She has been overrun by Stryia, a wicked half-human, half-shark sorceress with ambitions of dominating both land and sea using her army of sharks.