The Monster and the Willow is the eleventh episode of the first season of Winx Club. Stella complains about Flora's flowers in her room, and Tecna yells at her after she was saved from one of her plants. After being confronted about her plants Flora leaves to black mud swamp to study her plants where they wont bother anyone leading Bloom to scold them saying that even Flora shouldn't live in a swamp the Winx then go along to Black Mud Swamp in search for the Cheerful Gladioulus. They then meet up with the Undines (Water Nymphs). They reveal that the monster of the Black Island threatened them daily. They say they can't leave because their survival depends on a plant called Zillith, which can only be found on that island. The Winx decide to help them by going to the island to find an Undine named Lusiz who disappeared sometime ago and fight the monster. There they find that a Red Willow tree growing on the island makes all living creatures on the island fall asleep. They found little Luzis, who tells them that the monster was actually a turtle which was sleeping because of the Willow and which was sleepwalking. The Undines took it for a monster when it would move its head in and out of his shell during its sleep. Bloom and Flora in combined efforts, remove the Red Willow. Flora uses her rapid growth formula which multiplies the Zillith leaves. The Undines are so grateful that they reward Flora a Cheerful Gladioulus.