Brute and Glob are nightmares created by Morpheus.
Following Dream's disappearance, and the decay of the Dreaming, Brute and Glob decided to become the powers behind the throne, and set up their own version of Sandman. They took over Jed Walker 's dreams, and manipulated a scientist called Garrett Sanford in the hope of having a Sandman under their control. They confined themselves to the Dream Dimension, a small corner of the Dreaming that the duo cut off from the rest.
Garrett, however, snapped and killed himself. So, they took the dead man, Hector Hall, and made him into a superhero they called Sandman. Hector brought his still living wife, Lyta Hall, into the dream stream pocket of the Dreaming to live with him
When Morpheus found them during the incidents of The Doll's House, he banished them to "the darkness" for their insolence, and sent Hector Hall to the afterlife.
Brute and Glob later appeared as minor villains in the spinoff series, Lucifer and JSA. In their JSA appearance, they reveal what 'the darkness' was: pleasing dreams of children.