Sirena von Boo

Sirena von Boo is a character from the Monster High franchise.

Sirena is a hybrid, the child of a mermaid and a ghost, which makes her a mermaid ghost and a student at Monster High. Like her longtime hybrid friends—Avea, Bonita, and Neighthan—, Sirena has a history of going from school to school because she fit in nowhere. As a result, she is acutely aware of her double heritage that is making life so difficult for her. On the other hand, she would not trade her omni-mobility for anything in the world. She can travel underwater, float in the air, and pass through anything, and the possibilities this presents her with are endless. The only downside is that Sirena is easily distracted and the lack of barriers allows her to drift around on a whim without anyone able to follow or find her.

Appearance
Sirena Von Boo has stark white skin that flows over into the scales of a tail that changes from silver to blue to black at the bottom. Her long, ultramarine hair has lavender streaks through it and part of it is coiled and twisted, the rest flows down past her waist in side curls. She has blue eyes and from the elbow down her skin fades into black. She wears a golden or green one-shoulder top and has several long, black strands of fabric tied around her wrists. Her age is kind of weird because of her ghost heritage.

Personality
Sirena is sometimes described as an "air fin" because she loves to daydream and follow her imagination. She has a go with the flow attitude, and doesn't like to be pinned down. She loves hunting for treasure in the sea and frequenting antique shops on land. This curiosity about the unknown has translated into a love of archeology; she is highly interested in the world around her.

Abilities
Sirena inherited both the abilities of a Ghost and of a Mermaid:
 * Floating: As a ghost, Sirena can float, which comes in handy considering she has a fishtail and wouldn't be able to move outside of water
 * Permeation: Sirena can phase through solids and liquids easily, which gives her the ability to swim despite not being fully mermaid, but going through solids is from being a ghost.

Skillset
Being a mermaid, she also has some skillset of a mermaid:
 * Swimming: Sirena is a particularly great swimmer. She has created a great bond with Lagoona Blue because of their love for swimming.

Trivia

 * Her doll is shimmery white which fades into translucent black on her arms and black on her tail. In other media, her tail is slightly blue.
 * Since her introduction, she's also featured in several webisodes and was in Haunted as well, making her this to the other Freaky Fusion monsters.