by Seabie
+1/+1 Counters Theme: Ghavu, Guru of Spores + Mycoloth + Corpsejack Menace + Fungal Behemoth + Doubling Season (+ Cathar's Crusade + Protean Hydra, if you want to go 'offtopic')Spores Theme: Sporesower Thallid + Utopia Mycon + Thallid + Thallid Shell-Dweller + Deathspore Thallid + Sporoloth Ancient + Pallid Mycoderm + Psychotrope Thallid
Other good cards to consider: Mycoid Shepherd (raw power, but might not fit in very well with the other cards above), Fungal Shambler (unfortunately you have to splash blue for it, or you have to rely on other mana generating cards above...), Mold Shambler (nice removal!).