I'd recommend running 4 Strangleroot Geist . It's a must in any green stumpy deck.

What should I take out though? I'm thinking maybe swordwise centaur, but I'm not sure.

Yeah, Swordwise Centaur is a little weak in this deck, it's an ok card, but it's a little lackluster so I'd suggest taking it outl.

Sounds good. I'll change it as soon as I get my hands on some.

Karametra's Acolyte mabye very good ramp

I originally ran 4x Karametra's Acolyte but it was too slow. The way I see it, turn 3 1/4 or turn 3 Polukranos, World Eater .

Maybe add in Nykthos, Shrine to Nyx ? Otherwise, this looks pretty good- I just think you might consider cutting down on Nessian Wilds Ravager , unless you can cheat him in a little earlier

I'm considering Nykthos, Shrine to Nyx , but the problem is if I don't have any devotion yet it's useless. All my early game is all green mana. And I am probably going to take out Nessian Wilds Ravager for Khalni Hydra and/or Primalcrux .

As long as you get your small drops like Kalonian Tusker , Leatherback Baloth and Garruk's Companion , plus any of the mana dorks, out fast enough, you're going to build up big devotion early on, and hence Nykthos, Shrine to Nyx can show its power. Of course, the one thing to be careful about here is removal.

My problem is if I get one in my opening hand it's a dead card until turn 4.

It's actually useful on turn three, as long as you have a mana dork and two forests... I guess that as of the moment though, Nykthos, Shrine to Nyx would be more of a maybeboard card. Still, an option to consider.

tbh in an aggro deck you should win on turn 3-4 everytime , unless it is tokens.Here is some advice if you want to keep this deck. 24 forests and 2 Nykthos, Shrine to Nyx add a playset of Beast Within sideboard Nature's Claim and other stuff. like grafdiggers cage , add another color like red for Goblin Guide 1 Vexing Devil or white or black or something.Eternal Witness and Garruk Wildspeaker maybe take out Rancor take out Hydra Broodmaster and Nessian Wilds Ravager they are bad trust me if you want a 6 drop run Primeval Titan also Noble Hierarch is broken if you have the money. add Thrun, the Last Troll if you have money add Tarmogoyf add some Scavenging Ooze Skinshifter and if you add some forest ramp gotta love Dungrove Elder

also take out prey upon plus if you add white make everyone else sad with Thalia, Guardian of Thraben

you could splash her with Birds of Paradise + Noble Hierarch plus oh and I forgot add Utopia Sprawl and Elvish Visionary + plus take out the 2 mana 3/2 for Burning-Tree Emissary hope you use some of these. ( I have been playing modern 2-3 times a week for a long time) maybe Spellskite in sideboard

also if you want to play competitively don't play this, it's more of a casual deck. you should be able to on turn 3 with aggro but if its lifegain [ew] or control aggro you don't have to. Look at this if you wanna see what decks people are playing to make your sideboard better. http://www.mtgtop8.com/format?f=MO

one last thing if you use the cards to splash I told you you can run Blood Moon or Magus of the Moon if they resolve you will probably win unless it's affinity or a mono color deck .

Consider thinking your response out completely before flooding someone's feed, Towel. Mono green is competitively viable, it has a couple of top 8's in super IQs etc. However, I would agree that this is a little too weak to disruption. The mono G lists I have seen that have been successful eschew the ramp in favor of more immediate threats, using their non-creature spells to add pressure and evade disruption (Rancor , Vines of Vastwood , etc). I would agree that a couple of Beast Within s could do well in this list.

I'm liking what I see. I made a similar deck that utilizes all the devotion of these types of creatures. My original idea without the devotion looked more like what you have. I'll have to play test against this when I get a chance later.

Check out mine: Prey Upon This

Towel, I'm not splashing, this is staying mono green. Not negotiable. Also, I am taking out nessians and brood masters for Primalcrux and Khalni Hydra . I'm considering sideboarding beast within against some decks, but I wouldn't mainboard it. And finally, no, I'm not playing competitive. My lgs is very casual and this works great there and is fun for me and my opponents.

If you don't mind missing a T2 scary play, then the overgrowth/arbor elf combo does wonders. My deck likes to put out 7 drops (Spearbreaker Behemoth , Engulfing Slagwurm , Sylvan Primordial ) Turn 3.T1 Forest Arbor Elf T2 Forest Overgrowth T3 Big Scary

A bit expensive moneywise, but Tarmogoyf is always good in green. I'd recommend putting him in instead of Nessian. 6 mana for either a 12/12 or a 6/6 and a Prey Upon is too slow for Modern

If I ever get my hands on Tarmogoyf I'd have better things to do with it than put it in this deck. Also, if you look at the deck price, you'll notice I haven't put enough money into this deck to consider something so expensive. And finally, I've already decided what I'm taking the nessians out for.

Primordial Hydra could be fun in here.

With all the green mana symbols why not try Nykthos, Shrine to Nyx also Arbor Elf and Utopia Sprawl work very well together

Not interested in Nykthos, or any sort of Arbor Elf thing. Just not what I'm going for with this deck.