Mycoloth

Devour 2 (As this enters, you may sacrifice any number of creatures. This creature enters with twice that many +1/+1 counters on it.)
At the beginning of your upkeep, create a 1/1 green Saproling creature token for each +1/+1 counter on Mycoloth.

Shamanic Revelation

Draw a card for each creature you control.
Ferocious — You gain 4 life for each creature you control with power 4 or greater.

Llanowar Elves

Thromok the Insatiable

Devour X, where X is the number of creatures devoured this way (As this enters, you may sacrifice any number of creatures. This creature enters with X +1/+1 counters on it for each of those creatures.)

Taiga

Marwyn, the Nurturer

Whenever another Elf you control enters, put a +1/+1 counter on Marwyn, the Nurturer.
{T}: Add an amount of {G} equal to Marwyn's power.

Mountain

Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Pest Infestation

Destroy up to X target artifacts and/or enchantments. Create twice X 1/1 black and green Pest creature tokens with "When this creature dies, you gain 1 life."

Awakening Zone

At the beginning of your upkeep, you may create a 0/1 colorless Eldrazi Spawn creature token. It has "Sacrifice this creature: Add {C}."

Gruul Turf

Gruul Turf enters tapped.
When Gruul Turf enters, return a land you control to its owner's hand.
{T}: Add {R}{G}.

Forest

Apocalypse Hydra

Apocalypse Hydra enters with X +1/+1 counters on it. If X is 5 or more, it enters with an additional X +1/+1 counters on it.
{1}{R}, Remove a +1/+1 counter from Apocalypse Hydra: It deals 1 damage to any target.

Arachnogenesis

Create X 1/2 green Spider creature tokens with reach, where X is the number of creatures attacking you. Prevent all combat damage that would be dealt this turn by non-Spider creatures.

Artifact Mutation

Destroy target artifact. It can't be regenerated. Create X 1/1 green Saproling creature tokens, where X is that artifact's mana value.

Indomitable Might

Flash
Enchant creature
Enchanted creature gets +3/+3.
Enchanted creature's controller may have it assign its combat damage as though it weren't blocked.