William Miller, the author of the nursery rhyme "Wee Willie Winkie," was a Scottish poet who popularized the character of Willie Winkie as a personification of sleep. He added additional verses to the existing rhyme, creating a five-stanza poem that became well-known. The character of Wee Willie Winkie has since become a beloved figure in bedtime folklore, alongside other sleep-related entities like the Sandman and Ole Lukøje. Miller's creation continues to charm children and adults alike with its whimsical portrayal of a mischievous little boy who just won't fall asleep.