The odd beings that inhabit the realm known as the Dreaming in The Sandman have a hidden connection to DC Comics. Several of Morpheus' servants have a bond that goes beyond their work for the Lord of Dreams and honors a particular era in DC's history.
The lauded comic series The Sandman largely centers around Dream, aka Morpheus, one of seven siblings in a group of beings known as the Endless. Each of the entities embodies a concept such as death or desire for all life in the DC Universe. Morpheus rules over a realm known as the Dreaming, Sandman's most prominent location and the world where people visit when they dream. The fantastical land is populated by wonderfully charming and unusual characters such as Merv Pumpkinhead, Lucien, and the brothers Cain and Abel. While the Dreaming is home to many odd beings, these are some of Dream's most devoted workers.
However, there appears to be a connection shared between many residents of the Dreaming and other Sandman characters that even hardcore DC fans may have missed. The Sandman #2 by Neil Gaiman and Sam Kieth is titled “Imperfect Hosts”, which has a double meaning for a few select DC characters. Many characters introduced in the story are not original creations of Neil Gaiman, but characters who have been the 'host' of various DC horror and supernatural anthology books. For example, Cain and Abel were the hosts of the series House of Mystery and House of Secrets, and they both reside in their titular dwellings. Dream's righthand man Lucien was once the host of the title Tales of Ghost Castle. And the trio of witches Dream consults with to find his lost belongings were the recurring figures found in DC's The Witching Hour.
And the Dreaming’s residents weren’t alone. One of The Sandman's Endless, Destiny, is the only one of his siblings to not be created by Gaiman, as he also originated as the host of a DC anthology, Weird Mystery Tales. It'd be one thing if one or two characters that had served as hosts were given small parts in The Sandman, but the characters mentioned here all play crucial roles in the series. Given the nature of what The Sandman really is, it's clear that the hosts' inclusion was quite deliberate.
The Sandman is ultimately a story about stories. While the ongoing narrative of Morpheus makes up a large part of The Sandman, the world serves as a framing device to tell stories in the mysterious, dreamlike world its creators had fashioned. It was essentially trying to do the same thing books like House of Secrets and The Witching Hour did in years prior. These horror anthologies clearly influenced of the direction in The Sandman and having their hosts around was a way of acknowledging the books' impact. While characters like Cain and Abel weren't the stars of The Sandman, including them honored an important part of DC's history.