In addition to the venerable classical tradition of serving the loved ones of one's enemies to one's enemies ala Titus Andronicus, and all the way up to the liver and fava beans of Hannibal Lecter, one has the trope of the D&D innkeeper who Shanghais adventurers and other visitors from the rooms of the inn, and serves them for dinner.
I ran across this reference while reading a novel, and looked it up on the net ... it looks like it's totally, thoroughly unsubstantiated, but it's super D&D:
Is the Gygax Memorial Fund still Funded? Where is the Audit?
38 minutes ago