Miss Polly's Crackers was a brand that existed between 1905 and 1906 before it was discontinued. Ome person wrote to Miss Polly's Bakery saying that the crackers tasted like "Bad meat gone fly blown." None of Miss Polly's other products had any such problems. It turns out that the crackers had accidently became imbued with transubstantiation; in this case that of a rather ordinary mortal named Neil Mordane who worked at the bakery. There are a few boxes left over from that batch and they have a high price on the black arts black market.
This was something you needed to know.