When you meet him, he will introduce himself as THE Scarecrow of Oz. Emphasizing the word "THE." He is a proud artificial man, one of the four Libertarians of Oz that fought for freedom from The "3 W" (The Wicked Witch of the West) and now ruler of Oz, when The Wizard avocated the throne and went to parts unknown.
He had wished Dorothy would have taken up the throne and become Queen of Oz. She is his best friend, and savior. She saved him from being strung up in that corn field for so many years. She would have been a wonderful queen. He thinks. "The Wonderful Queen of Oz," He sighs.