Want something new to Minecraft that makes the game harder? How about JUST MAKING THE GAME HARDER!?
This behaviour pack keeps the look vanilla, but the hostiles are twice as damaging! A special effect of the Difficulties 7 to 9 Behavior Pack is that ALL mobs (except friendly ones that can attack or be ridden) have double the health, making it harder to get food, kill hostiles and defeat any boss! If you are wondering about arrows and explosions, they have been amplified by double as well! Not necessarily speed, but double the damage and power!
Also, please remember the packs cannot be loaded together at the same time, and it doesn't have a unique hash yet (as in it is still minecraft.net's default from their example pack), so you might run in to problems with other packs!
Gameplay video on YouTube has been removed until I stream another from the updated pack.
UPDATE: I noticed (with help, of course, in this topic. Thanks to TheRealReeper) that the more expertise you have, the better you could be at the pack. And this pack is kind of easy to experts... Therefore, I shifted Difficulties "7 to 9" to "4 to 6", and "7 to 9" will triple the damage and health of mobs in the new "4 to 6". One touch of a Zombie means INSTANT DEATH (if you don't have Iron Armor)!