Kelia B. Cortez

The shy tomboy of the group, Kelia B. Cortez — "Kelby" to her friends — is the new gill in Miami Beach. She has curly dark brown hair, big brown eyes behind a pair of reading glasses, and caramel-colored skin; in her mermaid form, her tail resembles that of a tiger shark, a beautiful dusty rose in color.

Kelby is revealed to be an Atavist, a rare genetic throwback who grew up as a human but discovered her ability to "turn tail" after moving from Arizona to Miami Beach and meeting the Rescue Sirens. Sporty and tomboyish but unsure of herself, Kelby’s shy around the other girls, and she's still very much getting the hang of this whole "mermaid" thing.

Despite growing up in a landlocked state, Kelby was always drawn to the water, and the only time she felt truly comfortable in Arizona was when she was doing laps in the pool. In her new form, she's gaining confidence, and she's teaching the mermaids as much about being a human as she is learning about being a mermaid — something Kelby secretly delights in, since she was never particularly popular or influential in her life back west. She's the only one of the Rescue Sirens who owns a car (a beat-up old Hyundai Tiburon), a cell phone, and a computer, so she becomes a main source of the Sirens' knowledge of human culture.

Kelby lifeguards at the local water park, Mako Splash, where she stashes her surfboard after her morning surf session and before her evening fix. She reads a ton of true crime novels and shares Pippa’s macabre fascination with horror movies, but Kelby’s real love is marine biology, which she studies at South Florida University.