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.)

Thunder of Hooves

Thunder of Hooves deals X damage to each creature without flying and each player, where X is the number of Beasts on the battlefield.

Manglehorn

When Manglehorn enters, you may destroy target artifact.
Artifacts your opponents control enter tapped.

Garruk's Packleader

Whenever another creature you control with power 3 or greater enters, you may draw a card.

Ravenous Baloth

Aether Charge

Whenever a Beast you control enters, you may have it deal 4 damage to target opponent or planeswalker.

Advocate of the Beast

At the beginning of your end step, put a +1/+1 counter on target Beast creature you control.

Wirewood Savage

Whenever a Beast enters, you may draw a card.

Krosan Warchief

Beast spells you cast cost {1} less to cast.
{1}{G}: Regenerate target Beast.

Rampaging Baloths

Trample
Landfall — Whenever a land you control enters, you may create a 4/4 green Beast creature token.

Leyline Prowler

Deathtouch, lifelink
{T}: Add one mana of any color.

Contested Cliffs

{T}: Add {C}.
{R}{G}, {T}: Target Beast creature you control fights target creature an opponent controls. (Each deals damage equal to its power to the other.)

Spiritmonger

Whenever Spiritmonger deals damage to a creature, put a +1/+1 counter on Spiritmonger.
{B}: Regenerate Spiritmonger.
{G}: Spiritmonger becomes the color of your choice until end of turn.

Molder Slug

At the beginning of each player's upkeep, that player sacrifices an artifact of their choice.

Threat

Create a 4/4 red and green Beast creature token with trample.

Thrash

Target creature you control deals damage equal to its power to target creature or planeswalker you don't control.

Thrash // Threat

Indrik Stomphowler

When Indrik Stomphowler enters, destroy target artifact or enchantment.

Sek'Kuar, Deathkeeper

Whenever another nontoken creature you control dies, create a 3/1 black and red Graveborn creature token with haste.

Ravenous Chupacabra

When Ravenous Chupacabra enters, destroy target creature an opponent controls.

Valley Rannet

Mountaincycling {2}, forestcycling {2} ({2}, Discard this card: Search your library for a Mountain or Forest card, reveal it, put it into your hand, then shuffle.)

Deathmist Raptor

Deathtouch
Whenever a permanent you control is turned face up, you may return Deathmist Raptor from your graveyard to the battlefield face up or face down.
Megamorph {4}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

Mold Shambler

Kicker {1}{G} (You may pay an additional {1}{G} as you cast this spell.)
When Mold Shambler enters, if it was kicked, destroy target noncreature permanent.

Baloth Null

When Baloth Null enters, return up to two target creature cards from your graveyard to your hand.

Noxious Groodion

Tooth and Claw

Sacrifice two creatures: Create a 3/1 red Beast creature token named Carnivore.

Ridgescale Tusker

When Ridgescale Tusker enters, put a +1/+1 counter on each other creature you control.

Fires of Yavimaya

Creatures you control have haste.
Sacrifice Fires of Yavimaya: Target creature gets +2/+2 until end of turn.