Mermaid Queen by Anna Santos

A handsome Lycan King will claim as his mate the mermaid who saved him from drowning.

All her mermaid life, Mirella has been told to stay away from the humans. Yet, one night, a mysterious pull compels her to save a handsome stranger from drowning in a shipwreck. Once she takes him to his island, the language barrier stops her from explaining to him that she’s his fated mate.
Duncan has been waiting for his fated mate. As the king of the Lycans, it’s his duty to marry and leave offspring. He never thought his mate could be a gorgeous mermaid. Despite being unable to communicate with her, he wants to make her his. But is she able to live out of water?
Mirella strikes a deal with the Sea Witch for the ability to speak the human tongue. Deeply in love with the stranger she keeps meeting on a beach, she’ll defy her father and will offer her tail to the witch to be with Duncan. But can she trust him with her heart and her life?

This is an adult fairy tale retelling of the Little Mermaid. This novella is not intended for readers under the age of 18.