<zgrep> misle/rn @/|a+b@| = { \xe2\x88\x9a(a\xc2\xb2-b\xc2\xb2) if a\xc2\xb2-b\xc2\xb2 \xe2\x89\xa5 0 ; i\xe2\x88\x9a(a\xc2\xb2-b\xc2\xb2) if a\xc2\xb2-b\xc2\xb2 < 0 }

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.