Path to Exile hits this deck hard.

Hi chaoswalker, my Hydras are protected by hexproof thanks to Asceticism and Vines of Vastwood, so Path to Exile is not a big problem.

Maybe add Treasure Cruise :3

WoestijnKonijn thank you for your suggestion!

Nykthos, Shrine to Nyx could be a good 1 of in the land base

Kegrat How many of them ??? And thanks to your suggestion

Probably one. It's really nice to draw, but it really sucks to draw two since it's legendary and unlike a creature you probably won't be replacing the first due to death in combat.

I'd only run 1 (maybe 2, but Im hesitant) since you dont have a way of discarding any extras. Its not necessary to win but in the games where you do draw it it'll rapidly accelerate you.

Thank you guys, i really apreciate your help.

i would recommend Hardened Scales in stead of Doubling Season, its cheaper and gives more +1/+1s and i didnt see a whole lot of tokens in your deck

SpiritoftheSands thank you for your suggestion, Hardened Scales is a good card but "slow" in my deck because i usually double the counters on my creatures with Corpsejack Menace and Solidarity of Heroes

A great mana ramp combo you could really use is Arbor Elf+Utopia Sprawl=Turn two Kalonian Hydra. My friends Hydra deck is dirty with this combo and Lifeblood Hydra

Matchu.76 thank you, very nice combo, well done Matchu.76 and Matchu.76's friend!!

I know it's already been suggested, but I'm going to make my argument for Bioshift because I don't see it in the decklist. It can be used as a means of saving counters if you're about to lose a creature, or you can attack, let your opponent declare blockers, then move a bunch of counters from one creature to another, such as one not being blocked. Also, it's a solid combo with Protean Hydra, and with Doubling Season or Corpsejack Menace in play it would be brutal. If you removed, say, five counters with Bioshift + Protean Hydra and have one of your doublers in play, you'd be putting ten counters on another creature and twenty on Protean Hydra. That's mean.

Also, it wouldn't have trample, but you could easily have a massive Fungal Behemoth.

ChrisPBakon thank you for your suggestion, i have already been using Bioshift for a long time, i know very well the card,the pros and the possible combis of that card. I cutted them off because i wanted protection spells like Vines of Vastwood, i run only 8/9 hydras, so i must protect them very well.

For Haste of Creatures, I prefer Surrak, the Hunt Caller instead of Hall of the Bandit Lord. Formidable in this deck is very easy to meet and you can use it each turn without giving up 3 life. Gyre Sage could be a good 2 drop for this deck as well. Maybe even Karametra's Acolyte.

Hi TheNight77, thank you for your suggestion, Surrak, the Hunt Caller is a good card but my 4 drop is Corpsejack Menace. What card would you replace with Surrak? My perfect game would be:

T1 forest --> mana dork

T2 hall of the bandit lord, mana dork

T3 forest/woodland cemetery, --> attacking 8/8 trampler (kalonian hydra) or Corpsejack menace without paying 3 life.

The number of cards in your deck doesn't support the ideal situation very well. The number of hydras (9) is perfect, giving you a strong chance of drawing average 2 but typically not more by turn 3 which is the earliest time you'd drop one. The 10 mana generating creatures though doesn't give a significant enough chance to draw 2 by turn 2, which would be ideal. 13-14 gives you the best chance of drawing 2 by turn 2.

At that point you might be concerned about drawing too many weenies in the late game if something bad should happen to your hydras. You may consider bigger bodied mana generating creatures who can block like Courser of Kruphix in order to stall until you can drop the hydras.

Try messing with this thing. It give interesting insight into the exact number balance of cards in a deck. Popluation size is deck size, number of successes is the number of cards you COULD DRAW, sample size is the number of cards you draw total (oppening hand +1 card for each turn after) and number of successes is the number of the card you WANT TO DRAW.

http://stattrek.com/online-calculator/hypergeometric.aspx

Thank you chaoswalker, yeah i suppose hypergeometric distribution could help me.

GregGreg, there really isn't any replacement for Surrak. Surrak is one of the very few mono green cards that give another creature haste. You could maybe go for an artifact like Lightning Greaves

TheNight77 i expressed myself badly, i mean, what of my cards you'd cut off to make space to Surrak. Sorry for my English

Inspiring Call can be a fun little trick against certain archetypes. Cool deck, +1

Jimmy_Chinchila thank you for your suggestion, certainly an interesting card, i usually have 1/2 max creatures with +1/+1 counters on it, so i don't know.

Since you want a lot of mana, Joraga Treespeaker looks better than Elvish Mystic here.
I really dislike playing the full 4 Asceticism, since drawing exactly one is reasonable, but drawing multiples is really bad since they are completely redundant. I would go down to something like 1-2 of them and play some Harmonize or Read the Bones instead. They can help find Asceticism if needed, but they are much better if you already have it or if what you need is lands or creatures.
For much of the same reasons, i also don't think Essence Harvest is a good 4-of, you usually don't want to draw multiples and it's only good if everything else is already working fine.
Surrak, the Hunt Caller has been suggested here before, and i have to second that. The card is very powerful and would fit your deck excellently. Hall of the Banditlord, in comparison, is okay, but since it's legendary and costs a lot of life, 3 copies seems too much. Why not play a mix of the two cards, for example 1 Hall and 2 Surrak?
Nissa, Voice of Zendikar looks like a fantastic card for your deck, it spits out some counters onto all of your creatures, which can then immediately get doubled by Kalonian Hydra or Corpsejack Menace.

Maybe try something with Hangarback Walker? Not a hydra but it can grow pretty fast with your set up (by turn even) and leaves board presence in case of a Wrath effect xD