Things You'll Need
Instructions
Begin the challenge. Both you and your opponent Garruk will be using green decks. Open by bringing out the Elvish Piper. Playing this card will cost you one permanent forest, but it allows you to bring out a creature card from your hand free of cost as soon as you play the Elvish Piper.
Use the Elvish Piper to bring out the Roughshod Mentor. Once the Roughshod Mentor is in place, and you have played three Grizzly Bears, attack with all three of those Grizzly Bears.
Wait until blockers are chosen. Once the blockers are assigned, play all three of the Giant Growths that you have on the single Grizzly Bear being blocked by the Elvish Pathfinder. Once that bear goes through, you'll deal the necessary 8 points of damage and defeat the challenge.