Crowley considers the person for a moment. He thinks he could tell if it were a demon. If it were one of his kind, hiding. They were so bad at it, first of all. Second, they gave off a distinctive smell, and he could usually detect it. But angels, they were a whole different story. He could always tell Aziraphale's scent, but that was just because Aziraphale was always around, and that was just part of what Crowley had become accustomed to. Another angel? Different story.

"Maybe we'll just stay quiet," he says, very serious. "Maybe they won't notice us."

With that, he puts the green blob into his mouth. And promptly starts loudly coughing at the intense, strange spice.