Mono-green can be a thing!
The tactic here is to get down as many beaters as possible and beat down the opponent as fast as possible, whilst trying to get a high devotion count for Nylea, God of the Hunt, Aspect of Hydra and Reverent Hunter.
The Creatures
Elvish Mystic helps me accelerate into my bigger guys quicker, which is always useful.
Experiment One is a 1-drop that can grow to be 5/5 or even 6/6 in the right circumstances, and can regenerate for no mana if needs be. Perfect to use with Pit Fight to kill their guy then regenerate.
Burning-Tree Emissary is basically a free 2/2 that gives me 2 devotion. What's not to love?
Scavenging Ooze can be used as a late game mana dump and life-gain engine, which is crucial in the aggro match-up. He becomes big when used properly and can exile things from graveyards if needs be.
Kalonian Tusker provides a cheap efficient body and 2 devotion. All in all very solid.
Courser of Kruphix gains life and filters through my deck, getting rid of all of the lands and allowing me to draw into more spells.
Reverent Hunter can be upwards of 7/7 when he comes into play, which is the epitome of the green mindset: big creatures, fast.
Nylea, God of the Hunt gives my guys trample, which is critical for a deck such as this; we don't want our 7/7 Reverent Hunter to be chump blocked. All this with a 6/6 indestructible body and a mana dump for later on.
Polukranos, World Eater acts as removal, which isn't exactly abundant in green. This alone makes him worth including. On top of that, he is a 5/5 that gets potentially huge with enough mana.
The Removal
Setessan Tactics is probably my favourite card that's been spoiled so far in Journey into Nyx because it gives mono-green some better removal. With enough mana, it's a one-sided board wipe. Worst case scenario, I have a ton of mana open and it becomes a mass pump spell. It's a win-win.
The Help
Aspect of Hydra is funny. It's a Giant Growth on steroids, delivering +6/+6 or more for just one mana. It acts as an excellent finisher and works well with Nylea, God of the Hunt and Pit Fight.
Nykthos, Shrine to Nyx is just there for loads of mana. Loads and loads of mana. This mana can be used to dump your hand, or for the abilities of Nylea, God of the Hunt, Polukranos, World Eater and Scavenging Ooze. Against the control match up, it also gives you a big Mistcutter Hydra to work with.