Sandman was a top notch criminal from Europe who decided to pay Gotham a visit and attempt to steal millions of dollars from one of the richest women in the world, J. Pauline Spaghetti. Being new to the city, he enlisted the help of Catwoman, though he planned to double-cross her and keep all the money for himself.
Sandman was a medical genius with outstanding knowledge of the mechanisms of sleep. He employed such knowledge in his capers. For example, he hoped to win J Pauline Spaghetti's confindence by curing her of her insomnia.
One of the most interesting things about Sandman was the fur coat he wore wherever he went. Perhaps he wore it because of its girth, the thickness which aptly hid the many instruments and gadgets he had hidden in inner pockets.
This version of The Sandman has not been in any other form of media.