The Fairy Godmother is a fairy with magical powers who acts as a mentor or godparent to someone in fairy tales.
In the DC Universe, the first Fairy Godmother introduced was named Halo, who debuted in the Angel Love Elseworlds comics. The second introduced was the "Fairy Godmother" of Bruce Wayne, who debuted in Detective Comics #614.
In the Arrowverse, the Fairy Godmother title is given to witches who take on the mantle from another witch, and cast spells after kids' wishes. The current Fairy Godmother is Nora Darhk, after taking the mantle from Tabitha in order to save Mona Wu's life.
The Fairy Godmother archetype was adapted by Barbara Slate, first appearing in Angel Love #3 (1986).