Munro Leaf

Wilbur Monroe Leaf (a.k.a. Munro Leaf) (December 4, 1905 – December 21, 1976) was an American author of children's literature who wrote and illustrated nearly 40 books during his 40-year career. He is best known for The Story of Ferdinand (1936), a children's classic which he wrote on a yellow legal-length pad in less than an hour. Labeled as subversive, it stirred an international controversy.
https://en.wikipedia.org/wiki/Munro_Leaf