The main strategy of the deck is to bring out beasts fast and hard and overwhelm the opponent.
Elvish Pioneer and
Wirewood Savage are used to ramp up mana as fast as possible.
Krosan Warchief is naturally used as a beast leader to reduce cost and give regenerate (mostly to itself).
Brushstrider is cheap and allows for some early threat.
Barkhide Mauler is used early on for card draw, but can be used later as a simple 4/4 beast as well.
The main threat and win condition in the deck are the four Rhox. Rarely you'll have only one, but more likely than not you're gonna get two or three by the time the game is over. Its ability to deal direct damage and its regenerative powers means you attack as often as possible without too much risk. If it's blocked and can survive, you deal damage to the player. However, it's possible that the opponent might have even beefier creatures; that's where Giant Growth comes into play.
Krosan Colossus is just there kind of as a misleading threat. Its beefy nature means it can hardly be ignored when it attacks, and it stays relatively safe with Krosan Warchief's regenerate. However, a counter-tactic is to simply throw cannon fodder at it since it does not have trample...
Finally, AEther Charge is there for some extra damage while having synergy with Beast Within to turn my early elves into more beasts. And naturally Giant Growth is a bit of a surprise when people think they can finally take down a beast if I exhausted too much mana for Krosan Warchief's regenerate.
Overall, this is just my favourite tribal aggro deck; create big creatures fastly.