Let the buyer beware (Gaunt shop)
Leland Gaunt is the antagonist in the Stephen King horror novel, Needful Things, published in 1991.
The story is set in the small fictional town of Castle Rock, Maine, where a new shop named "Needful Things" opens, to the curiosity of the townspeople, all greeted by the seemingly kind old man, Leland Gaunt, and they all ignore the sign hanging in his shop, "Caveat emptor" ("Let the buyer beware").
Leland Gaunt is described as an older man, appearing physically to be in his late 50s or early 60s, with graying hair. He is extremely charming, gentlemanly, and urbane -- the very ideal of the perfect small town shop proprietor.
Mr. Gaunt's eyes change color depending on the observer.
Mr. Gaunt's palms are unlined.
It is suggested in the novel that Leland Gaunt is actually the devil, or at least a demon of some power.