Coin Man is an enemy listed in the Enemies bestiary table.
Nothing else about it is recorded anywhere on this wiki: no floor, no health, no damage, no drops and no behaviour. Its name suggests a link to Gold and so perhaps to the Gilded Halls, but no source read for this wiki says so, and the guess is recorded here only as a guess.
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.