Somebody retorts to some threat, request, or demand with "Oh yeah? You and what army?" The phrase is supposed to be one of defiance, as if to say it will take an army to stop/defeat them. Unfortunately for the speaker, the addressee in question typically has a very good, and very literal, answer. They just point over a hill / summon The Undead / beckon for their ninja minions to immediately [...] [tvtropes.org]