Stomping Ground

({T}: Add {R} or {G}.)
As Stomping Ground enters, you may pay 2 life. If you don't, it enters tapped.

Ghor-Clan Rampager

Trample
Bloodrush — {R}{G}, Discard Ghor-Clan Rampager: Target attacking creature gets +4/+4 and gains trample until end of turn.

Borderland Ranger

When Borderland Ranger enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Signal the Clans

Search your library for three creature cards and reveal them. If you reveal three cards with different names, choose one of them at random and put that card into your hand. Shuffle the rest into your library.

Acidic Slime

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When Acidic Slime enters, destroy target artifact, enchantment, or land.

Mountain

Forest

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Frenzied Tilling

Destroy target land. Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Arbor Elf

Burning-Tree Emissary

When Burning-Tree Emissary enters, add {R}{G}.

Rubblehulk

Rubblehulk's power and toughness are each equal to the number of lands you control.
Bloodrush — {1}{R}{G}, Discard Rubblehulk: Target attacking creature gets +X/+X until end of turn, where X is the number of lands you control.

Sylvan Primordial

Reach
When Sylvan Primordial enters, for each opponent, destroy target noncreature permanent that player controls. For each permanent destroyed this way, search your library for a Forest card and put that card onto the battlefield tapped. Then shuffle.

Wasteland Viper

Deathtouch
Bloodrush — {G}, Discard Wasteland Viper: Target attacking creature gets +1/+2 and gains deathtouch until end of turn.

Rootbound Crag

Rootbound Crag enters tapped unless you control a Mountain or a Forest.
{T}: Add {R} or {G}.

Borborygmos Enraged

Trample
Whenever Borborygmos Enraged deals combat damage to a player, reveal the top three cards of your library. Put all land cards revealed this way into your hand and the rest into your graveyard.
Discard a land card: Borborygmos Enraged deals 3 damage to any target.