A paperback anthology that I recently looked into was Half-Human compiled by Bruce Coville. This is a collection of short stories dealing with beings and creatures who are part human and part something else, like mermaids, gorgons, and centaurs.
One of these tales is titled Scarecrow by Gregory Maquire who wrote the Wicked trilogy. This takes place sometime just prior to The Wizard Of Ozwhere the Scarecrow is a normal scarecrow which suddenly realizes that it is alive in some way. It's a pretty good read, even though the story is only 20 pages long. Whether or not this directly ties into the Oz storyline shown in Wicked is unknown, but it makes for a decent side-story to the series.