Prevent all combat damage that would be dealt this turn.

Rootwalla

{1}{G}: Rootwalla gets +2/+2 until end of turn. Activate only once each turn.

Elvish Mystic

Enlarge

Target creature gets +7/+7 and gains trample until end of turn. It must be blocked this turn if able. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)

Swamp

Briarpack Alpha

Flash (You may cast this spell any time you could cast an instant.)
When Briarpack Alpha enters, target creature gets +2/+2 until end of turn.

Staff of the Wild Magus

Whenever you cast a green spell or a Forest you control enters, you gain 1 life.

Rumbling Baloth

Doom Blade

Advocate of the Beast

At the beginning of your end step, put a +1/+1 counter on target Beast creature you control.

Brindle Boar

Accursed Spirit

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Deadly Recluse

Reach (This creature can block creatures with flying.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Mind Rot

Vial of Poison

{1}, Sacrifice Vial of Poison: Target creature gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Kalonian Tusker

Corpse Hauler

{2}{B}, Sacrifice Corpse Hauler: Return another target creature card from your graveyard to your hand.

Forest

Plummet

Garruk's Horde

Trample
Play with the top card of your library revealed.
You may cast creature spells from the top of your library. (Do this only any time you could cast that creature spell. You still pay the spell's costs.)

Giant Growth

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

Woodborn Behemoth

As long as you control eight or more lands, Woodborn Behemoth gets +4/+4 and has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Into the Wilds

At the beginning of your upkeep, look at the top card of your library. If it's a land card, you may put it onto the battlefield.