Old-Growth Troll

Trample
When Old-Growth Troll dies, if it was a creature, return it to the battlefield. It's an Aura enchantment with enchant Forest you control and "Enchanted Forest has '{T}: Add {G}{G}' and '{1}, {T}, Sacrifice this land: Create a tapped 4/4 green Troll Warrior creature token with trample.'"

Ancient Imperiosaur

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Trample, ward {2}
This creature enters with two +1/+1 counters on it for each creature that convoked it.

Scavenging Ooze

{G}: Exile target card from a graveyard. If it was a creature card, put a +1/+1 counter on this creature and you gain 1 life.

Bristling Boar

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

Llanowar Elves

Giant Growth

Target creature gets +3/+3 until end of turn.

Shifting Ceratops

This spell can't be countered.
Protection from blue (This creature can't be blocked, targeted, dealt damage, enchanted, or equipped by anything blue.)
{G}: This creature gains your choice of reach, trample, or haste until end of turn.

Return to Nature

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Exile target card from a graveyard.

Almighty Brushwagg

Trample
{3}{G}: This creature gets +3/+3 until end of turn.

Forest

Steel Leaf Champion

This creature can't be blocked by creatures with power 2 or less.

Yorvo, Lord of Garenbrig

Yorvo enters with four +1/+1 counters on it.
Whenever another green creature you control enters, put a +1/+1 counter on Yorvo. Then if that creature's power is greater than Yorvo's power, put another +1/+1 counter on Yorvo.

Setessan Petitioner

When this creature enters, you gain life equal to your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)

Elvish Mystic

Hungering Hydra

This creature enters with X +1/+1 counters on it.
This creature can't be blocked by more than one creature.
Whenever this creature is dealt damage, put that many +1/+1 counters on it. (It must survive the damage to get the counters.)

Aspect of Hydra

Target creature gets +X/+X until end of turn, where X is your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)

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.

Kronch Wrangler

Trample
Whenever a creature you control with power 4 or greater enters, put a +1/+1 counter on this creature.