The only reason Fuminori notices Toothless is his hyper-awareness of other creatures, and even then, Toothless gets pretty close before Fuminori looks up. He tenses, then relaxes a little; Toothless is the only other person in Wonderland that Fuminori can recognize on sight.

Not that he really wanted to be caught eating human flesh, even by a dragon. But the dragon is the most likely of the other residents to be unbothered by it, so Fuminori doesn't scramble to hide it like he might if approached by another human.

"Hey."