Critics in general have deprecated the characterizations of The DreamQuest of Unknown Kadath, noting that little space is devoted to character development. Nearly all critics agree that Randolph Carter is in fact H. P. Lovecraft, himself, and that the character's rediscovery of Boston parallels Lovecraft's return to Providence after unhappy years in New York. Carter's joy at seeing the glories of Boston is taken to reflect Lovecraft's joy at seeing Providence again.

In addition to Carter, the novel is populated by a host of eccentric characters that are as bizarre as the Dream World itself. For instance, there are the cats from Ulthar, who live double lives in the waking world and the dreaming one. They keep track of their friends and help Carter when he needs them.

Too, there is Nyarlathotep, "the Crawling Chaos," an Elder God who knows the secret of unknown Kadath. The evil one...