As a young boy, Neil Gaiman was different.
He did his first reading at the age of four and never stopped.
While other kids played soccer or Cowboys and Indians, Gaiman spent much of his time in the library,
gulping down one book after another, sorting out what he liked and what not.
Thus he met the first requirement for a writer: to be a reader himself.
From the Ocean at the End of the World:
"I liked myths. They weren't adult's stories and they weren't children's stories. They were better than that. They just *were*."
Gaiman is (very) well versed in mythology and frequently uses it as a starting point for his own stories. They abound with ghosts, gods, ghouls and numerous other supernatural creatures whose names do not start with a g. Sometimes they are friendly but more often the stuff of nightmares; often they have their own agenda, treating mortals as mere playthings.
"Ah," said Wednesday, with a monkey grin, "so do you have mighty bacchanals in her honour? Do you drink blood wine under the full moon, while scarlet candles burn in silver candle holders? Do you step naked into the seafoam, chanting ecstatically to your nameless goddess while the waves lick at your legs, lapping your thighs like the tongues of a thousand leopards?"
Especially Egyptian, Greek and Norse mythology appear often in Gaiman's tales. A special case is his book Norse Mythology, which on first sight appears as another lore based Gaiman story, then reveals itself as a retelling of Old Norse myths that you can find in older translations and finally turns out to be a more smooth, whole and readable mold of those tales that very probably would have delighted the skalds that created the originals as much as the modern reader.
However do not think that Gaiman is confined to rehashing old stories.
If you want to classify him, he is a fantasy writer, ingenious and eloquent.
Just search the Sandman for one character's rebuff of a complaint of lack of inspiration and your head will dazzle with possibilities.
He did not start out that way, at first making his living as a journalist.
But when he read Alan Moore's Swamp Thing, he decided to make a career out of creative storytelling.
From Sandman, Collectors:
It seemed like the late autumn wind blew them in that night, spinning and dizzying them from the four corners of the world. It was a bitch wind, knife-sharp and cutting, and it blew bad and cold. And they came with it, scurrying and skittering, like yellow leaves and old newspapers from a thousand places and from nowhere at all. They came in their suits and their tee shirts, carrying rucksacks and briefcases and suitcases and plastic bags, muttering and humming and silent as the night. It seemed like the bitter fall wind brought them there. Perhaps it did.
Once Gaiman had started writing, he did not stop (he still reads too).
By now his oeuvre has grown large.
It is also wide: it encompasses short stories, novellas, novels, comics, scripts for movies and television shows.
Throughout his career, his style has deepened but he has never forgotten his love of stories when he was a child,
so he still writes for both children and adults.
He has won several Hugo and Nebula awards and other awards.
He has carved his words so deep into modern folklore that when he dies, he will probably become a myth himself, being told and retold for generations.
From Sandman, The Kindly Ones:
And he called out to the thunder, "Strike me dead," but the thunder wouldn't, because he was dead already. And he ran to the fire, and begged the fire to burn him up. But the fire couldn't burn him, for the chill of death put it out ... And he threw himself in the water, and he screamed, "Drown me blue," but the water wouldn't, for the earth-color was coming into his face already, and the water tossed him out. And last of all, he throws himself onto the ground, onto the middenheap, and prays for the worms to come and eat him, so he could rest in his grave, and beguit of the woman.
Gaiman's best known works are the comics series Sandman, the novel American Gods and the young adult novel The Graveyard Book, but there is a lot more. Look him up at his own website, at https://www.neilgaiman.com/.