Frontier Mastodon

Ferocious — This creature enters with a +1/+1 counter on it if you control a creature with power 4 or greater.

Acidic Slime

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When this creature enters, destroy target artifact, enchantment, or land.

Evercoat Ursine

Trample
Hideaway 3, hideaway 3 (When this creature enters, look at the top three cards of your library, exile one face down, then put the rest on the bottom in a random order. Then do it again.)
Whenever this creature deals combat damage to a player, if there are cards exiled with it, you may play one of them without paying its mana cost.

Burst of Strength

Put a +1/+1 counter on target creature and untap it.

Forest

Llanowar Elves

Blossom Prancer

Reach
When this creature enters, look at the top five cards of your library. You may reveal a creature or enchantment card from among them and put it into your hand. Put the rest on the bottom of your library in a random order. If you didn't put a card into your hand this way, you gain 4 life.

Wild Growth

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G}.

Forced Adaptation

Enchant creature
At the beginning of your upkeep, put a +1/+1 counter on enchanted creature.

Outmuscle

Put a +1/+1 counter on target creature you control, then it fights target creature you don't control. (Each deals damage equal to its power to the other.)
Adamant — If at least three green mana was spent to cast this spell, the creature you control gains indestructible until end of turn.

Savage Punch

Target creature you control fights target creature you don't control.
Ferocious — The creature you control gets +2/+2 until end of turn before it fights if you control a creature with power 4 or greater.

Gnarlid Colony

Kicker {2}{G} (You may pay an additional {2}{G} as you cast this spell.)
If this creature was kicked, it enters with two +1/+1 counters on it.
Each creature you control with a +1/+1 counter on it has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Fangren Firstborn

Whenever this creature attacks, put a +1/+1 counter on each attacking creature.

Beast Whisperer

Whenever you cast a creature spell, draw a card.

Colossal Dreadmaw

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Gnarlid Pack

Multikicker {1}{G} (You may pay an additional {1}{G} any number of times as you cast this spell.)
This creature enters with a +1/+1 counter on it for each time it was kicked.

Ambush Viper

Timberpack Wolf

This creature gets +1/+1 for each other creature you control named Timberpack Wolf.

Alpine Grizzly

Sylvan Anthem

Green creatures you control get +1/+1.
Whenever a green creature you control enters, scry 1.