Definition:
Mock-Heroic - satirizes the heroic style by using it to describe something trivial.


Example:
“At this point they came in sight of thirty or forty windmills that are on that plain.‘Fortune,’ said Don Quixote to his squire, as soon as he had seen them, ‘is arranging matters for us better than we could have hoped. Look there, friend Sancho Panza, where thirty or more monstrous giants rise up, all of whom I mean to engage in battle and slay, and with whose spoils we shall begin to make our fortunes. For this is righteous warfare, and it is God's good service to sweep so evil a breed from off the face of the earth."
~ Miguel de Cervantes Saavedra, Don Quixote


Explanation:
In this passage, Don Quixote reveals to his squire that he believes the windmills on the plain are actually giants, and that he must defeat them in a glorious manner in order to serve God. The reader knows that the windmills really are just windmills, so it is humorous to hear Quixote to speak of them in such a lofty manner. The way this story is written is to poke fun at other, similar narratives written in a serious manner to portray the heroics of men. Thus, it is mock-heroic.