What Is a Tuffet?

In the "Little Miss Muffet" rhyme, the titular character is said to sit on a tuffet, which can be seen either as a tufty clump of grass or a small stool similar to a pouffe. However, because Miss Muffet is said to be frightened away from her seat by a spider, it may be safe to assume that, in this context, the referenced tuffet is a clump of grass rather than a piece of furniture.