Experiment One

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
Remove two +1/+1 counters from this creature: Regenerate it. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Life Goes On

You gain 4 life. If a creature died this turn, you gain 8 life instead.

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Dryad Militant

({G/W} can be paid with either {G} or {W}.)
If an instant or sorcery card would be put into a graveyard from anywhere, exile it instead.

Steel Leaf Champion

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

Thrun, the Last Troll

This spell can't be countered.
Hexproof (This creature can't be the target of spells or abilities your opponents control.)
{1}{G}: Regenerate Thrun.

Dungrove Elder

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Dungrove Elder's power and toughness are each equal to the number of Forests you control.

Avatar of the Resolute

Reach, trample
This creature enters with a +1/+1 counter on it for each other creature you control with a +1/+1 counter on it.

Pelt Collector

Whenever another creature you control enters or dies, if that creature's power is greater than this creature's, put a +1/+1 counter on this creature.
As long as this creature has three or more +1/+1 counters on it, it has trample.

Treetop Village

This land enters tapped.
{T}: Add {G}.
{1}{G}: This land becomes a 3/3 green Ape creature with trample until end of turn. It's still a land. (It can deal excess combat damage to the player or planeswalker it's attacking.)

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.

Unravel the Aether

Choose target artifact or enchantment. Its owner shuffles it into their library.

Blossoming Defense

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

Forest

Rancor

Enchant creature
Enchanted creature gets +2/+0 and has trample.
When this Aura is put into a graveyard from the battlefield, return it to its owner's hand.

Collector Ouphe

Activated abilities of artifacts can't be activated.

Strangleroot Geist

Haste
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

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.)

Dismember

({B/P} can be paid with either {B} or 2 life.)
Target creature gets -5/-5 until end of turn.

Vines of Vastwood

Kicker {G} (You may pay an additional {G} as you cast this spell.)
Target creature can't be the target of spells or abilities your opponents control this turn. If this spell was kicked, that creature gets +4/+4 until end of turn.