What Dr. Seuss books have Maisy in them?

There is no character named Maisy in any Dr. Seuss books. Maisy is a character created by Lucy Cousins, not by Dr. Seuss (Theodore Seuss Geisel).

Maisy is the star of a series of children's books known for their bright colors and simple stories.

Dr. Seuss is known for books like "The Cat in the Hat", "Green Eggs and Ham", "Horton Hears a Who!", and many more.