Sentence:  The idea of a merchant selling both totems of pure evil and frozen yogurt (he calls it frogurt!) is amusing in itself, as is the idea that frogurt could be cursed, but it's really the Shopkeeper's quicksilver shift from <WSD>ominous</WSD> doomsaying to chipper salesmanship that sells the sequence. 
Meaning of the word marked with <WSD> tags:  Specifically, giving indication of a coming ill; being an evil omen