Mrs. Worthington

Mrs. Worthington is the titular antagonist of the same episode from R.L. Stine's The Haunting Hour, a series of supernatural horror stories aired for young children - similar to the Goosebump franchise but often having darker endings and bigger consequences for the children involved.

History
Mrs. Worthington is a mysterious paranormal entity akin to a fairytale witch who began "life" as little more a boy's collection of drawings, his way to cope with continual bullying by his older sister: he envisioned Mrs. Worthington as an embodiment of his own suppressed desire for vengeance and continually wished for her to become real and punish his sister for tormenting him.

One night the boy's wish is somehow granted and when his parents leave his older sister in charge Mrs. Worthington arrives in the guise of a babysitter and begans plans to exact the boy's revenge - she shows off her collection of torture devices and the boy instantly realizes the danger he has put his sister in, he begs Mrs. Worthington not to enforce his wish and claims he did not truly desire harm to his sister.

Mrs. Worthington reluctantly agreed to this if his sister could behave appropriately but despite the boy trying to warn his sister she was rude to Mrs. Worthington as well as unrelenting in her attitude towards her younger brother, which convinced Mrs. Worthington that the sister was beyond redemption and in need of "proper" punishment.

After magically imprisoning the older sister and literally zipping her mouth shut she prepared a voodoo doll of the boy's mother, whom she intended to also punish for raising such a spoiled child: the boy was horrified at how Mrs. Worthington was twisting his wishes and went upstairs to try and free his sister.

Eventually the siblings do manage to bond and the older sister realizes just how her bullying had impacted her brother when she learns he was the one who accidentally summoned Mrs. Worthington.

When Mrs. Worthington comes upstairs and scolds the brother for freeing his sister the boy grew angry and confronted Mrs. Worthington directly, claiming she was far worse than a simple bully (like his sister) and maybe she deserved to be punished - this angered Mrs. Worthington and she used her magic to create a doll of the boy and threatened to cut off his tongue with scissors as punishment.

Luckily for the siblings a picture of Mrs. Worthington lay on the floor and the boy realized that by harming the picture he could also harm the monster he summoned - he managed to defeat Mrs. Worthington by tearing the picture up, causing the witch to fall to pieces.

The end of the story has brother and sister in a happier relationship, with the sister having apparently learned her lesson (and no doubt grateful for her brother saving her life) - meanwhile, in the upper room of the house, Mrs. Worthington's disembodied hand is seen sketching a new picture of Mrs. Worthington, presumably bringing the evil spirit back to life.