It was Sir Hokus of Pokes, the first recurring character that Ruth Plumly Thompson added to Oz. He’s an old knight that Dorothy and the Cowardly Lion find in The Royal Book of Oz (1921). He moves to the Emerald City and plays a supporting role in several more adventures, rather as L. Frank Baum used the Shaggy Man. He’s not rounded, and I doubt he’s many people’s favorite, but he becomes a comfortable part of the fabric of Thompson’s Oz.
As such, Sir Hokus reflects Thompson’s sensibility, based on older European fairy tales. In contrast, Baum’s usually tried to find magic in contemporary American culture for Oz.
Lewis Carroll’s White Knight, he’s an old man, still active but gray. In both respects, he’s removed from his prime period, no longer able to undertake all the quests he yearns for.
As a result, the character is no longer the least bit interesting. Sir Hokus’s foundational conflict has been resolved. Even though Dorothy looks in the younger man’s eyes and says he’s the same friend she knew, it’s no surprise that he makes only token appearances in the rest of Thompson’s series.
John R. Neill liked drawing Sir Hokus so much, evidently, that he brought the old knight back in his three Oz books, once more chasing dragons without being able to slay them. Neill offered no explanation of how, but neither consistency nor logic was part of his storytelling.