It's probably a good thing that Fiddleford lost the lights that used to shine from his body when he cut his Arcade keycard in half, because when his slitted pupils snap toward the source of that snort they aren't accompanied by an eerie blue glow. This is already a disturbing enough image as it is, and he knows that, which is why he makes a sort of distressed gurgle around the legs sticking out of his bizarrely contorted face. He's never actually seen what it looks like when he does the whole 'unhinge your jaw and butterfly open your ribs and swallow a whole human' trick and he doesn't ever really want to, but he has to imagine it's very unfun to see without warning.

In the absence of any sort of ability to explain or reassure vocally, he holds up a hand in a way that might be meant to communicate 'it's okay, you're not next' or maybe just 'hold on a second my mouth is full'.