The Sandman is the king of sleep, the physical embodiment of sleep itself. He resides in a tall castle apparently made of sand in the middle of a forest, counting sheep indefinitely in a futile attempt to go to sleep. He has purple skin and pointed ears, and wears a purple pointed hat that curls above his head, a black eye-mask, a pink jumpsuit, purple curly toed shoes, and a black cloak.
During The Sandman Sleeps, he becomes infuriated that he can't sleep, and upon hearing Muriel snoring, comes to the farmhouse to steal the magical sand that allows her to sleep. As a result, he is able to go to sleep, where as Muriel spends several sleepless nights becoming more and more fatigued, and losing her grip on reality. When taking her for a night drive to try and help her sleep, Courage hears the Sandman snoring, and enters his castle to try and recover Muriel's sand. The Sandman awakes, but refuses to give back the sand, despite Courage attempting to waylay him going back to sleep by lying in his bed. While doing so, Courage discovers the Sandman's teddy, an old and battered panda cuddly toy. Overjoyed at having his teddy back, and claiming that him losing it must be why he couldn't sleep, the Sandman gives Courage back the sand.