Pacify. GG sir. I'd throw a thing or 2 in that makes the combo a bit harder to stop. While any sort of card denial will be a pain (save destruction), any tap locks or ability stoppers could stall it just long enough to cost you the game. A Dmir Infiltrator with an encoded Hands of Binding is enough to stop it with only 2 cards and 4 mana, and it works with any unblockable or fear/intimidate that isn't white. Life gain stall can be quickly outpaced too, if that's all there is (since the creatures are tiny). Cradle of Vitality is nice for pumping cards and I've seen it do great things with Goldenglow Moth, especially if you throw in lifelink. Righteousness is really good with Goldenglow Moth and lifelink as well. Righteousness, lifelink, goldenglow and High Ground is 22 life for -4 and 3 mana and whatever the lifelink costs.
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Make sure you have the means to reliably get red mana if you're gonna make it part red. Nothing worse than red in hand and no red mana available. I have a similar deck based off waiting a bit but scavenging and snowballing and I've found Gravecrawlers to be tremendously helpful, especially with Golgari's plethora of plant zombies. It's also great food to endlessly feed Varolz cuz he gets targeted FAST and can be hard to keep out without making him bigger or making him a lame duck. Also, if you don't mind losing standard, I love Vulturous Zombie to pieces though it's probably a bit too late game for your purposes.
Trestle Troll is good against flying.