"Fanciful of Magic and Folklore" was written by J.K. Rowling.
There were and are many such authors.JRR Tolkien, the brothers Grimm, JK Rowling etc
One notable writer known for fanciful tales of magi and folklore is the Brothers Grimm. Jacob and Wilhelm Grimm collected and wrote down numerous fairy tales from European oral traditions, including stories like "Cinderella," "Snow White," and "Rapunzel."
There were and are many such authors.JRR Tolkien, the brothers Grimm, JK Rowling etc
Thomas Mann wrote The Magic Mountain.
Sarah Prineas wrote The Magic Thief.
Davis Pratt has written: 'Magic animals of Japan' -- subject(s): Animals, Folklore, Tales 'Magic animals of Japan' -- subject(s): Tales, Animals, Folklore
John B. Sebastian from the Lovin' Spoonful wrote Do You Belive In Magic.
Henry Schoolcraft
If you mean in the Harry Potter books, Bathilda Bagshot wrote a History of Magic.
Pilot
Australian writer and artist Norman Lindsay (1879-1969) wrote The Magic Pudding.
The Magic Finger was written by Roald Dahl.