Attrition - There are far better removal cards, and although it does get more creatures into the graveyard since you are also sacrificing; something like Deathmark , Go for the Throat , Snuff Out or Sever the Bloodline are better.Gigantiform - I see this card working in a 60 card format, but not Commander. The kicker is useless, and it can easily be countered. I would suggest removing it.Overgrown Tomb - While shock-lands are generally expensive, they can be extremely useful in multiple situations. I would seriously consider adding one in.You're running a bit low on mana, even with the signet, cluestone and keyrune. That's one of green's greatest strengths (mana-ramping). Maybe adding Verdant Eidolon , Utopia Mycon , or Somberwald Sage might really help. There are sorceries that do this also.Some creatures that make players sacrifice creatures would help you a lot Xathrid Demon , Desecration Demon or Demon of Death's Gate . Note: these make you sac. something to; but consider how you have almost 40 creatures, you're covered.Massacre Wurm would also be a great addition to your deck.

First of all, you need more land. With very few exceptions, I would always run at least 36 (this deck is not an exception). Also, I recommend the two staples of varolz, Death's Shadow and Phyrexian Dreadnought . Also, Inkmoth Nexus is very good in varolz.

Death's Shadow and Phyrexian Dreadnought are hilarious good with your commander.

Phyrexian Soulgorger might be good too.

Things like Death's Shadow , Phyrexian Dreadnought , Phyrexian Soulgorger and Force of Savagery I've often seen in Varolz decks and they are brilliant.

Attrition I like because it only takes up one card slot but it's a multiple use kill spell

Gigantiform of course the kicker is useless but I still think it's a good enchantment, I've used it and it works

Land has been an interesting thing. I have played games where I am horribly mana screwed but more often than not it's worked well actually (sometimes too much land too). If I can get my hands on the expensive lands it would definitely improve the flow, but I probably won't anytime soon because I really don't want to be pouring that much into this deck.

I do like Desecration Demon a lot (I have him in another deck with Heartless Summoning and it's so much fun).

For the lands:

Cut out Golgari Guildgate and Golgari Rot Farm : They are simply too slow and from my experience mana fixing isn't that much needed in a 2 color EDH.

For the instants:

Cut out Death Wind for Ultimate Price : EDH has a lot of big creatures floating around and this way you can deal with most of them for less mana. Snuff Out is extremely good. Try it out too. I found it very useful.

Death Wind is one of the cards I was never positive about having but it seemed useful enough. But you're right Ultimate Price is much better. That or Go for the Throat as grimjosher suggested

Or Snuff Out . It is really good since you can litteraly always cast it. If you have mana or not doesn't matter.

Very true, I'll keep an eye out to see if it comes into the local store (I just checked and they don't have any). I feel like if I take out the guildgate or rot farm I should replace with Terramorphic Expanse maybe?

The creatures you have in this deck are just too tiny in my opinion, you are run green and black you have access to some serious bombs. I'd love to talk about your deck some I also run Varolz as my commander i've only been playing it for a little over month but if you wanna check it out. http://tappedout.net/mtg-decks/varolizzle-foshizzle/Just add me i'd love to share some of the things that have really worked for me because a lot of the cards im seeing in your deck were in mine at first and I have cut a lot of them. Just hit me up if you want

@MartialArt , I agree that there is a better option than death wind, I have to disagree with putting in ultimate price murder is much better even if it cost that extra black. I had to cut ultimate price because most generals and multicolored creatures are way to abundant to be limited like that.

I would play both + Snuff Out SCApikeman. Ultimate Price is still great for other creatures and if there are too many multicolors in the meta there's still Rend Flesh and Doom Blade that are also great.

I'll check some stores see if they have Snuff Out . but definitely will replace Death Wind with Go for the Throat over Ultimate Price or Murder

SCApikeman I checked out your deck and yeah there are some stuff there that I'll consider but the main thing in this deck is have a lot of chumps, graveyard fodder and expendable creatures I can sac. so far the deck has done really well in multiplayer, and I don't think I could do a total overhaul of the deck.

why not run Golgari Grave-Troll ?