Archetype of Aggression

Creatures you control have trample.
Creatures your opponents control lose trample and can't have or gain trample.

Ogre Battledriver

Whenever another creature you control enters, that creature gets +2/+0 and gains haste until end of turn. (It can attack and {T} this turn.)

Goblin Anarchomancer

Each spell you cast that's red or green costs {1} less to cast.

Boartusk Liege

Trample
Other red creatures you control get +1/+1.
Other green creatures you control get +1/+1.

Gruul Spellbreaker

Riot (This creature enters with your choice of a +1/+1 counter or haste.)
Trample
During your turn, you and this creature have hexproof.

Mountain

Zhur-Taa Goblin

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

Sinuous Predator

This creature can't be blocked by more than one creature.

Kessig Prowler

Kessig Prowler // Sinuous Predator

Burning-Tree Emissary

Bloodbraid Elf

Haste (This creature can attack and {T} as soon as it comes under your control.)
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

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.

Domri, Chaos Bringer

+1: Add {R} or {G}. If that mana is spent on a creature spell, it gains riot. (It enters with your choice of a +1/+1 counter or haste.)
−3: Look at the top four cards of your library. You may reveal up to two creature cards from among them and put them into your hand. Put the rest on the bottom of your library in a random order.
−8: You get an emblem with "At the beginning of each end step, create a 4/4 red and green Beast creature token with trample."

Karplusan Forest

{T}: Add {C}.
{T}: Add {R} or {G}. This land deals 1 damage to you.

Beast Whisperer

Whenever you cast a creature spell, draw a card.

Rootbound Crag

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