The King is a character in Babbitty Rabbitty and her Cackling Stump who appears in both the real and in-universe versions of The Tales of Beedle the Bard.
Story[]

The King "learning magic"
The King has decided to keep all the magic in the world for himself. He forms the Brigade of Witch-Hunters to hunt true witches and wizards with wild hounds. But the King needs to learn magic and issues a proclamation to the kingdom to find an instructor with magical abilities. Nobody with true magic is willing to respond out of fear. However, a charlatan who is very cunning, arrives at the palace to lie and says he is a very powerful wizard despite having no real magical knowledge or skills.[1]
After persuading the King he has magical skills after performing a few simple tricks, the charlatan agrees to teach him in exchange for money, rubies, one silver chalice and fame. The charlatan teaches the King in the palace gardens. He fashions "wands" out of a twig and they spend their days waving their "wands" in the air and shouting nonsense. One day, the washerwoman, Babbitty Rabbitty, watches them wave their twigs, hop in circles and pronounce meaningless rhymes. Being a real witch, she laughs hysterically from her cottage window.[1]
The King is humiliated and tired of learning. He wants to perform in front of his subjects to prove his new abilities. When the charlatan tries to tell the King that he suddenly has to leave town for a faraway land and is unavailable to help during the show, the King threatens to have the Bridgade hunt him if he leaves and if anyone laughs during the performance, he will chop his head off.[1]
The next day, the King performs his "magic" in front of a crowd. At first, he produces real spells and entertains the amazed crowd by vanishing a woman's hat and levitating a horse. In truth, the King is not really performing the spells because the chalartan has threatened Babbitty Rabbitty, who is a real witch, into hiding and producing the spells for the King. However, when the Captain of the Brigade of Witch-Hunters asks the King to bring the dead hound Sabre back to life, Babbitty does nothing because she knows magic cannot revive the dead. The King tries in vain and when the crowd begins to laugh, he demands to know why the spell isn't working.[1]
To save himself, the charlatan reveals Babbitty hiding in a bush and says she is a wicked witch who is blocking their spells. Babbitty runs with the hounds of the Bridgade pursuing her after the King sends them after her. When the King and his subjects discover the hounds barking at a tree, the charlatan tells him the evil witch has turned herself into it. He suggests they cut it down so the King orders an axe and they fell the tree. However, when they start to leave, the stumps starts cackling.[1]
They hear the voice of Babbitty Rabbitty telling them real witches and wizards can't be cut in half and they should try cutting the charlatan in two to prove it. He panics and confesses to being a fraud so the King has him taken to a dungeon. She also tells them the King is now cursed for killing a witch and that if any more are harmed, the King will feel the physical pain like an axe stroke in his side.. She also demands that the King build a statue of her on top of the stump to remember the harm they've caused to witches and wizards. The King agrees and promises to fulfill her demands and leaves the scene. He didn't realise that Babbitty has survived the attack by transforming into a rabbit and then left the kingdom. The King stayed true to his promise - he disbands the Bridgade and builds a statue of Babbitty on top of the stump forever after.[1]