Savage Smash

Target creature you control gets +2/+2 until end of turn. It fights target creature you don't control. (Each deals damage equal to its power to the other.)

Voracious Hydra

Trample
This creature enters with X +1/+1 counters on it.
When this creature enters, choose one —
• Double the number of +1/+1 counters on this creature.
• This creature fights target creature you don't control.

Skarrgan Hellkite

Riot (This creature enters with your choice of a +1/+1 counter or haste.)
Flying
{3}{R}: This creature deals 2 damage divided as you choose among one or two targets. Activate only if this creature has a +1/+1 counter on it.

Uncivil Unrest

Nontoken creatures you control have riot. (They enter with your choice of a +1/+1 counter or haste.)
If a creature you control with a +1/+1 counter on it would deal damage to a permanent or player, it deals double that damage instead.

Gruul Beastmaster

Riot (This creature enters with your choice of a +1/+1 counter or haste.)
Whenever this creature attacks, another target creature you control gets +X/+0 until end of turn, where X is this creature's power.

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."

Regenesis

Return up to two target permanent cards from your graveyard to your hand.

Gruul War Plow

Creatures you control have trample.
{1}{R}{G}: This artifact becomes a 4/4 Juggernaut artifact creature until end of turn.

Mossfire Valley

Colossus

Target creature gets +4/+2 and gains trample until end of turn.

Collision

Collision deals 6 damage to target creature with flying.

Collision // Colossus

Ravager Wurm

Riot (This creature enters with your choice of a +1/+1 counter or haste.)
When this creature enters, choose up to one —
• This creature fights target creature you don't control.
• Destroy target land with an activated ability that isn't a mana ability.

Wildwood Scourge

This creature enters with X +1/+1 counters on it.
Whenever one or more +1/+1 counters are put on another non-Hydra creature you control, put a +1/+1 counter on this creature.

Ragefire

Ragefire deals 3 damage to target creature.

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.

Ironscale Hydra

If a creature would deal combat damage to this creature, prevent that damage and put a +1/+1 counter on this creature.

Terror of the Peaks

Flying
Spells your opponents cast that target this creature cost an additional 3 life to cast.
Whenever another creature you control enters, this creature deals damage equal to that creature's power to any target.

Goblin Gathering

Create a number of 1/1 red Goblin creature tokens equal to two plus the number of cards named Goblin Gathering in your graveyard.

Zhur-Taa Goblin

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

Mountain

Kazandu Refuge

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {R} or {G}.

Benevolent Hydra

Benevolent Hydra enters with X +1/+1 counters on it.
If one or more +1/+1 counters would be put on another creature you control, that many plus one +1/+1 counters are put on it instead.
{T}, Remove a +1/+1 counter from Benevolent Hydra: Put a +1/+1 counter on another target creature you control.

Gargos, Vicious Watcher

Vigilance
Hydra spells you cast cost {4} less to cast.
Whenever a creature you control becomes the target of a spell, Gargos fights up to one target creature you don't control.

Rootbound Crag

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

Bolrac-Clan Crusher

{T}, Remove a +1/+1 counter from a creature you control: This creature deals 2 damage to any target.

Khenra Charioteer

Trample
Other creatures you control have trample.

Forest

Rhythm of the Wild

Creature spells you control can't be countered.
Nontoken creatures you control have riot. (They enter with your choice of a +1/+1 counter or haste.)

Game Trail

As this land enters, you may reveal a Mountain or Forest card from your hand. If you don't, this land enters tapped.
{T}: Add {R} or {G}.

Sunder Shaman

This creature can't be blocked by more than one creature.
Whenever this creature deals combat damage to a player, destroy target artifact or enchantment that player controls.

Frenzied Arynx

Riot (This creature enters with your choice of a +1/+1 counter or haste.)
Trample
{4}{R}{G}: This creature gets +3/+0 until end of turn.