Du Bois's style of illustration was unique, distinctive, and immediately recognizable. He was educated primarily in France, and that surely influenced his work, giving it a European---or at least a non-American---flair.
His writing was equally inimitable, and he received the Newberry Medal for "The Twenty-One Balloons". (He also received two Caldecott Honors for his illustrations.)
His imagination was without boundaries; today some commentators call his work "science fiction"..a sort of Jules Verne for the younger set.
He loved his koala bears,
but humans and animals of all kinds
populate his books.Many of his titles are still in print---and for good reason! I encourage you to re-aquaint yourself with this artist's charming and stimulating work.