• Unspeakable Symbol

Often an auto-win if T2 Skullbriar, the Walking Grave followed by a T3 Unspeakable Symbol. Also, insane synergy with Winding Constrictor, Hardened Scales, and Corpsejack Menace (and Pir, Imaginative Rascal).

A more expensive suggestion is to avoid lands that enter tapped and also reduce the number of lands that don't produce black or green (and adding Lotus Petal for some potential turn one plays). Getting Skullbriar, the Walking Grave into play one turn earlier makes a huge difference:

1. More likely to get through before opponents get blockers into play (early growth also increases the probability to get through on later turns).
2. Exponential growth; adding an additional attack is often the difference between a win or a loss.