Rubblebelt Rioters

Haste
Whenever this creature attacks, it gets +X/+0 until end of turn, where X is the greatest power among creatures you control.

Rubblehulk

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

Ruric Thar, the Unbowed

Vigilance, reach
Ruric Thar attacks each combat if able.
Whenever a player casts a noncreature spell, Ruric Thar deals 6 damage to that player.

Ghor-Clan Rampager

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

Scorchwalker

Bloodrush — {1}{R}{R}, Discard this card: Target attacking creature gets +5/+1 until end of turn.

Mountain

Rubblebelt Raiders

Whenever this creature attacks, put a +1/+1 counter on it for each attacking creature you control.

Zhur-Taa Druid

{T}: Add {G}.
Whenever you tap this creature for mana, it deals 1 damage to each opponent.

Slaughterhorn

Bloodrush — {G}, Discard this card: Target attacking creature gets +3/+2 until end of turn.

Zhur-Taa Goblin

Riot (This creature enters with your choice of a +1/+1 counter or haste.)

Nikya of the Old Ways

You can't cast noncreature spells.
Whenever you tap a land for mana, add one mana of any type that land produced.

Forest

Wasteland Viper

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