Savage Ventmaw

Flying
Whenever this creature attacks, add {R}{R}{R}{G}{G}{G}. Until end of turn, you don't lose this mana as steps and phases end.

Aggressive Mammoth

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Other creatures you control have trample.

Llanowar Visionary

When Llanowar Visionary enters, draw a card.
{T}: Add {G}.

Forest

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

Keeper of Fables

Whenever one or more non-Human creatures you control deal combat damage to a player, draw a card.

Blossoming Defense

Target creature you control gets +2/+2 and gains hexproof until end of turn.

Mountain

Boulder Rush

Target creature gets +2/+0 until end of turn. (Then exile this card. You may cast the creature later from exile.)

Rimrock Knight

Rimrock Knight // Boulder Rush

Ram Through

Target creature you control deals damage equal to its power to target creature you don't control. If the creature you control has trample, excess damage is dealt to that creature's controller instead.

Zhur-Taa Goblin

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

Once and Future

Return target card from your graveyard to your hand. Put up to one other target card from your graveyard on top of your library. Exile Once and Future.
Adamant — If at least three green mana was spent to cast this spell, instead return those cards to your hand and exile Once and Future.

Khenra Charioteer

Trample
Other creatures you control have trample.

Domri, City Smasher

+2: Creatures you control get +1/+1 and gain haste until end of turn.
−3: Domri, City Smasher deals 3 damage to any target.
−8: Put three +1/+1 counters on each creature you control. Those creatures gain trample until end of turn.

Harmonize

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.)

Clan Guildmage

{1}{R}, {T}: Target creature can't block this turn.
{2}{G}, {T}: Target land you control becomes a 4/4 Elemental creature with haste until end of turn. It's still a land.

Llanowar Elves

Domri's Ambush

Put a +1/+1 counter on target creature you control. Then that creature deals damage equal to its power to target creature or planeswalker you don't control.

Clamor Shaman

Riot (This creature enters with your choice of a +1/+1 counter or haste.)
Whenever Clamor Shaman attacks, target creature an opponent controls can't block this turn.