Tom is a hard-minded and fiercely greedy man whose desire for wealth dictates his every action. He lives a cheerless existence in an unfurnished house, constantly engaging in bitter disputes with his wife. When presented with an opportunity for massive wealth, his sheer miserliness overrides any moral hesitation or fear of the supernatural. He approaches dark bargains with a self-assured, stubborn confidence.

Old Scratch is the devil incarnate, manifesting as a gruff woodsman with a soot-blackened face and coarse black hair. He guards the buried treasure of the pirate William Kidd and actively seeks to recruit human souls by offering wealth in exchange for moral corruption. He views usurers and those who profit from the misery of others as his particular people.

Tom's unnamed wife is a violent, turbulent woman whose greed matches or exceeds her husband's. She secretly hoards valuables from him and responds to the news of hidden treasure with immediate, ruthless ambition. Her overwhelming desire for wealth drives her to seek out the devil on her own terms when Tom initially hesitates.

William Kidd is a historical pirate who buried an immense fortune deep in a thickly wooded morass. He made a pact with the devil to protect the money but died before he could reclaim it, leaving his gold under supernatural guardianship for generations.

Deacon Peabody is an outwardly respectable religious leader in the local community. Despite his pious public image, he engages in shrewd and questionable bargains with the local Indigenous populations, hiding a corrupt interior beneath his holy reputation.

Absalom Crowninshield is a wealthy and influential man in the colony who made his fortune through piracy. The Puritan society reveres him as a great man, oblivious to his true moral standing and his association with the dark forces residing in the swamp.

The Speculator is a former friend of Tom Walker who loses his fortune in risky land investments. Facing total ruin during a time when money is scarce, he turns to Tom for a loan, only to find himself trapped by punishing interest rates and the threat of foreclosure.

Diedrich Knickerbocker is a fictional Dutch New York historian who serves as the narrator of the tale. He presents the supernatural legend as an authentic piece of local lore, maintaining a scholarly distance while recounting the dark events that befell the Walker household.