C182 The murderer is not a cat

The boy's expression was terrible, not like a normal person at all. His voice grew louder as he bounced on the pungent liquid.

"Red tongue?" I looked at his bright red tongue, then at the pale tip of the dead cat's mouth. "Are you telling me how to tell a corpse from a living person?"

I made a bold guess, but after saying that, even I felt that it was unreasonable