This is a green deck (duh) that uses Grizzly Bears as attakckers early on, 
then switching out for much larger creatures later. Here it is: 

4x Llanowar Elves 
3x Grizzly Bears 
2x Spined Wurm 
1x Panther Warrior 
2x Redwood Treefolk 
1x Pincer Spider 
1x Spike Colony 
1x Spike Soldier 
1x Spike Feeder 
1x Trained Armodon 
1x Lone Wolf 
1x Llanowar Elite 
1x Plated Rootwalla 
2x Ukatabi Wildcats 
1x Rabid Wombat 

1x Jorael's Favor 
1x Ancestral Mask 
1x Frog Tounge 
1x Whip Silk 
1x Web 
1x Regeneration 
1x Tiger Claws 
1x Predatory Hunger 

3x Monstrous Growth 
1x Wing Snare 
1x Squall 
1x Stream of Life 
1x Lure 

1x Fog 
1x Venomous Breath 
1x Giant Growth 
1x Explosive Growth 

17x Forest