Kalia has long dark blue hair adorned with pink and yellow flowers. She has blue eyes, light yellow eyeshadow and orange-colored lipstick. She wears a necklace decorated with yellow pearls and red mittens with pearls. Once transformed, it has an orange fabric-decorated bra with leaves, yellow ruffles on the shoulders and a long orange tail with sequins decorated with light yellow ruffles on the front and flowers at the waist.
Her nostrils, canines teeth and her bones are more prominent. Her hair and skin gets paler and her tail loses the brightness and the yellow fins. Her brassiere is now squared, light blue and divided in the middle with a dark blue circle in the left and a strip in the right side. Instead of mittens she wears light blue hand cuffs with three spikes each, and dark blue shoulder pads.
Kalia is a very gentle and sweet mermaid. She is very helpful and protective to her friends. Like Flora, Kalia loves and defends underwater nature. Kalia is Flora's best friend underwater.
In "Valtor's Mark," Kalia is holding her tired, weakened friend Celina as both try to survive the storm. A tidal wave appears but both are saved by Aisha. But later we can see her like a mer-monster with the other mermaids who Valtor transformed.
Kalia appears again in "The Sea of Fear" as a mer-monster with other mermaids who attacked the Winx. They succeeded in catching her and turning her back into a normal mermaid but their spell did not work and she has become a mer-monster again.
Next she appears in "One Last Fluttering of Wings" as a mer-monster who fight with mermaids for conquering Andros. She attack Bloom and Tecna, then Bloom defeated her with Fire Sphere and Kalia falls in water.
Shee appears once more in "Wizard's Anger" along with Celina and Tala. The three mermaids dance happily in frnt of Queen Ligea, overjoyed that their kingdom and sisters are restored. Tressa swims into the cavern and embraces her friends. Kalia, Celina, Tressa and Tala swim through their healed ocean kingdom.
In Perle, Vires kidnapped Tala, Kalia, Celina and other mermaids and transformed them into black pearls capturing their vital energy. They were released and transformed back by of Ligea's sacrifice.
In Magic Ocean CD's book, Tala, Kalia and Celina, among other mermaids, they disappear, imprisoned by Vires, being freed by the Winx in the end.
- Kalia's name is a Hawaiian name and means "the flower wreath; the beloved"; its alternate form is Kalei.