The coin is just a shade smaller than a US half dollar, coming in at 28.5mm in diameter and 8.9g in weight. And it is nonagonal in shape (your word of the day! meaning 9-sided), which is certainly an odd shape. But it looks pretty cool. It came in two versions, one copper and one silver (I will get to the silver one at a later date) neither of which were for general circulation. Even so, 200,000 were minted so not exactly a rare coin.
The obverse is a depiction of a lady drinking champaign at a ball (the operetta is not about a bat, but about a ball in Vienna, Austria in the 1800's). In the upper left are the words "DIE FLEDERMAUS" (The Bat in Austrian/German) and among the cluster of champaign bubbles is a flying bat. It is a fine little bat of some kind, looking very much like an insectivorous bat from Europe. The nose is a bit cat-like instead of bat-like, but that is such a small detail!