Invisible City

Brazilian television series Invisible City (Cidade Invisível) takes place in a world where mythical beings live in secret among humans. Set in Rio de Janeiro, environmental detective Eric finds himself drawn into this world after his wife is killed in a mysterious fire. Not long afterward, other people start dying one by one in similar ways, and it all seems connected to a development project that will encroach the jungle that used to be these beings' home.

One of the beings that Eric meets is a siren-type mermaid named Camila, played by Jessica Córes. She has the ability to hypnotize people, and has pulled many men to their deaths in the ocean. In the show she's mostly in her human form, but she's briefly seen with a CGI tail at the end of episode 2 and at the beginning of episode 3.