Redditor "famousmess" posted an image to the pareidolia subreddit
, showing a gum mark he saw on the floor of the subway that looks like Edgar Allan Poe. What subway, I don't know.
He concedes it's possible that it might be stencil art. However, he notes that, "it's real small and the same general size of the other gums... I know some street artists and showed them, consensus is gum but who knows. It would be a silly spot and size to get noticed."
Edgar Allan Poe (for the sake of comparison)