And there are even modern examples. If "The Saga Begins" by Weird Al Yankovic (parody of "American Pie") isn't a mock epic, I don't know what is. It has all the elements of an epic, and it manages to be hilarious at the same time.
One might even say "Bohemian Rhapsody" by Queen is something of a mock epic. Or "A Quick One While He's Away" by The Who could be a micro rock opera, or a mock epic. It's a matter of perspective, I guess, but these all strike me as poking more than a little fun at the genre.