Well to suggest something different...why does the monster have to be big?
Why not have a grand mage imp who can cast devestating spells?
I like the idea of a prolonged battle...in which case it lasts say 10 minutes.
Or when you and your opponent command a large army,that would take time to finish.
If we go back to the big bad monster thing I assume that if the monster does hit you in all likelyhood you will lose say most of your hitpoints.
One thing I would like to see are monsters using the surrounding objects e.g boulders...fallen tress or even uprooting a tree to use as a club.
