I’m new to CoCth, but I never let being new to a game or a lack of research stop me from asking someone to hold my beer.

I’m developing a kind of monster for a homebrew setup, and they need to eat something about humans that leaves dead bodies, but I can’t decide on what. Spinal fluid? Eyes? Blood vessels? Do they need to eat lungs in order to breathe Earth’s atmosphere?

Suggestions for how they get whatever it is out/off of the body would also be welcome.

EDIT: Thank you, everyone, for the great suggestions. I'm going with the frontal cortex consumed in the most direct way possible. It has serial killer/B-movie vibes for me, and I can think of ways that the press/police could gloss over some unsettling details publicly that would be very obvious to, say, a coroner or observant detective.