<ais523> ` printf \'#include <stdio.h>\\nint main(void) { float C = 4.0; printf("%%f", C/C++); }\' | gcc -fno-diagnostics-color -Wall -Wextra -x c /dev/stdin

Ghouls are undead that eat BRAINS. So basically, bog standard undead like zombies or wights, but with some fancy back story in the book that nobody reads.