Belinda's Witch appeared in the episode "The Tale of the Bookish Babysitter". She was portrayed by Natalie Radford, who also portrayed Belinda. For unknown reasons, the appearence has been left uncredited. Possibly to hide the fact it was a dual role or simply because the witch was a minor character.
She is a hideous and terrifyingly evil witch. One who is also a cannibal that likes to prey on and eat children.
She was created as a manifestation of the malevolent part of Belinda's Imagination. She was contained inside a story book. The intent was for her to appear as an illusion. She was meant to appear to make the story seem real and then disappear afterwards. That is, only when her story was read properly word from word and page to page and finished.
Then when Ricky Winter starting reading her story, he did not finish it. Therefore she escaped the book and entered the real world. Also, she either teamed up with or placed a spell on the Knight from Belinda's other book "The Knight's Sword" (another book he started and did not finish). In which she also placed a curse on the King. She turned him into a tortured ghost, doomed to wonder the earth forever.
Once she escaped, she realized she had to destroyed Belinda's book. Or else, once they were read and finished she would become imprisoned back into fiction again. So she boarded up the doors to the Winter's family kitchen. Then she begun burning Belinda's book. She also transformed into Belinda to deceive and fool Ricky into helping her. Her deception worked and Ricky helped her burned all of the books. Then the real Belinda revealed to Ricky that she was an impostor. Then she revealed her true horrifying face and she tried to grab him and he ran from her screaming.
She teamed up with the Knight. Then they both begun chopping their way through the barricade to get into Ricky's kitchen. Belinda revealed to Ricky that she did indeed have intentions on eating him. So he needed to start creating a new story to return her and all the other manifestations back to realm of fantasy and fiction.
Then a little while later, Ricky begun imaging and creating Belinda's new storybook "The Dark Tomb". She knew that if Ricky finished the book, the King would be freed from his cursed and rightfully restored to his throne. Also she wanted to set her sights on Ricky and eat him too.
So she first put on a facade. She disguised herself as an innocent little girl who got lost. She tried to convince him that she was lost and needed help. So she begged him for his help and to put the book down. Ricky realized that she was not only from another time but also from another story. Then she changed back scaring him out his wits. She almost made him lose the book too.
Then Ricky quickly picked up the Knight's longsword and slit her across the chest. She screamed in agony as green slime purged from her body. Then she was destroyed, leaving nothing behind but a pile of slimy clothing.