In Gene Wolfe's SF short story, The Man in the Pepper Mill, a description is provided of a book with a pirate captain with a long mustache, wearing yellow robes embroidered with a black dragon. It's probably a classic of "boy's literature" but also could be a comic book or Golden Age SF.
The book was easily twice as good as it had appeared, with many brightly colored pictures of strange ships with billowing sails and snapping banners. There were pirates, and men blacker than the man down the street Tippy's mother said was black even though he was not, and a captain with a long yellow robe with a black dragon on it and a long, long mustache. It was all interesting, and some of it was very interesting -- so interesting that Tippy kept going back to those pictures again and again so he could study them and then look out to sea and imagine himself on whatever kind of ship it was.
I don't necessarily need to find the exact book, but I am trying to identify the pirate captain character. For example, perhaps it's a character from the old Prince Valiant strip. Or it could be Ming the Merciless, but he wears red.