Becca is the most practical of the mermaids, coming from a chaotic background, she would constantly plan things to make life neat and orderly. She has a tendency to be organised and efficient, with a quick-thinking and responsible attitude.
She is strong and brave, as when she defended herself against three rusalka. It can also be noted that Becca is sure of herself and is quite intelligent.
Becca has curly red hair, freckles and blue eyes and a pearly beige tail with patches of brown.
When she is first introduced in the book, she wears gold-rimmed glasses, a pearl necklace, hair combs and carries a traveling case.
In Dark Tide, she wears a jacket. Astrid, while practicing pipe magic, turns her face bright yellow, her tail silver and makes snakes sprout from her head.
Becca was orphaned at a young age when her father died of mercury poisoning and her mother was killed by longline hooks.
She went to an orphanage and when she was older she became a worker at the songpearl shop Baudel.
Becca appears near the end of Deep Blue, where she meets the group (Ava, Ling, Serafina, Neela, Astrid, and the Iele). She takes place in temporarily destroying Abbadon's image and also in the bloodbind. She is last seen swimming through Vraĵa's mirror into Rorrim's realm, the mirror world.
Becca is seen in one convoca in the book. She isn't mentioned after that in the second book.
Becca, while travelling through Atlantica, meets up with Astrid accidently and, though reluctant at first, team up together to survive. She soon discovers Astrid's lack of magic and Astrid confesses that her parents might have been ashamed. Becca admits to Astrid that what she said about her parents and her life in Atlantica was a story; she is an orphan. Becca helps Astrid make magic by creating a whale bone pipe. She becomes good friends with Astrid. She then leaves to find her talisman and successfully retrieves it and meets the new Praedatori leader Marco and his sister Elisabetta. She soon develops feelings for Marco and discovers he likes her as well. However, Becca believes their relationship can't be possible as she is a mermaid and Marco is a human and, even though she loves him, tells him that they are both "very stupid". She then leaves Marco and Elisabetta and meets up with Serafina, Neela, Ling and Astrid at the Black Fin Resistance's new base in the Kargord.
Becca is first seen in the book when she angers Neela by waking her up, when she goes to find a lava seam. Becca is involved in the Battle for Cerulea and when they go to fight Abbadon.
- "Becca" is the short form of the name "Rebecca", which derives from the Hebrew name "Rivqah" that means "to tie firmly", "snare", "noose", "tied up" or "secured".