Overrun

Creatures you control get +3/+3 and gain trample until end of turn.

Tyvar, the Pummeler

Tap another untapped creature you control: Tyvar, the Pummeler gains indestructible until end of turn. Tap it.
{3}{G}{G}: Creatures you control get +X/+X until end of turn, where X is the greatest power among creatures you control.

Elven Chorus

You may look at the top card of your library any time.
You may cast creature spells from the top of your library.
Creatures you control have "{T}: Add one mana of any color."

Nature's Claim

Destroy target artifact or enchantment. Its controller gains 4 life.

Nylea's Forerunner

Trample
Other creatures you control have trample.

Doubling Cube

{3}, {T}: Double the amount of each type of unspent mana you have.

Triumph of the Hordes

Until end of turn, creatures you control get +1/+1 and gain trample and infect. (Creatures with infect deal damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Old One Eye

Trample
Other creatures you control have trample.
When Old One Eye enters, create a 5/5 green Tyranid creature token.
Fast Healing — At the beginning of your first main phase, you may discard two cards. If you do, return Old One Eye from your graveyard to your hand.

Mana Reflection

If you tap a permanent for mana, it produces twice as much of that mana instead.

Giant Ankheg

Trample
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Other creatures you control have trample and ward {2}.

Numa, Joraga Chieftain

At the beginning of combat on your turn, you may pay {X}{X}. When you do, distribute X +1/+1 counters among any number of target Elves.
Partner (You can have two commanders if both have partner.)

Wellwisher

{T}: You gain 1 life for each Elf on the battlefield.

Frantic Strength

Flash
Enchant creature
Enchanted creature gets +2/+2 and has trample.

Vernal Bloom

Whenever a Forest is tapped for mana, its controller adds an additional {G}.

Brawn

Trample
As long as Brawn is in your graveyard and you control a Forest, creatures you control have trample.

Bear Umbra

Enchant creature
Enchanted creature gets +2/+2 and has "Whenever this creature attacks, untap all lands you control."
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.