Jonson had in mind when he wrote:

"He may, perchance, in tail of a sheriff's dinner,
Skip with a rime o' the table, from near nothing,
And take his almain leap into a custard,
Shall make my lady Maydress and her sisters,
Laugh all their hoods over their shoulders."

It was once widely believed that a stone of magical, medicinal qualities
was set in the toad's head, and so Shakespeare wrote:

"Sweet are the uses of adversity;
Which, like the toad, ugly and venomous,
Wears yet a precious jewel in its head."

"A Midsummer Night's Dream" is the most wonderful fairy story in the
world, but Shakespeare did not create it out of hand; he found the fairy
part of it in the traditions of the country people. One of his most
intelligent students says: "He founded his elfin world on the prettiest
of the people's traditions, and has clothed it in the ever-living flower
of his own exuberant fancy."

This immense mass of belief, superstition, fancy, is called folk-lore
and is to be found in all parts of the world. These fancies or faiths or
superstitions were often distorted with stories, and side by side with
folk-lore grew up the folk-tales, of which there are so many that a man
might spend his whole life writing them down. They were not made as
modern stories are often made, by men who think out carefully what they
are to say, arrange the different parts so that they go together like
the parts of a house or of a machine, and write them with careful