The Unfinished One is an enemy of Wax World.
It is one of the three enemy types named on the Wax World page, alongside the Wax Knight and the Melted Wizard. Wax World is the secret floor reached by returning to the starting room after the Gilded Halls boss is defeated.
No health, damage, drop or behaviour figures have been recorded for it.
This is a stub. The Enemies table lists this enemy but has never carried a description, and its table image is a placeholder borrowed from another enemy. Nothing about it was found in the Steam guides, forum threads or the official manual read for this wiki, so everything above is all that is currently recorded. If you meet one in game, this page is worth filling in.