Prevent all combat damage that would be dealt this turn.

Crop Rotation

As an additional cost to cast this spell, sacrifice a land.
Search your library for a land card, put that card onto the battlefield, then shuffle.

Green Sun's Zenith

Search your library for a green creature card with mana value X or less, put it onto the battlefield, then shuffle. Shuffle Green Sun's Zenith into its owner's library.

Once Upon a Time

If this spell is the first spell you've cast this game, you may cast it without paying its mana cost.
Look at the top five cards of your library. You may reveal a creature or land card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Forest

Manamorphose

Add two mana in any combination of colors.
Draw a card.

Elvish Spirit Guide

Exile Elvish Spirit Guide from your hand: Add {G}.

Mox Diamond

If Mox Diamond would enter, you may discard a land card instead. If you do, put Mox Diamond onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add one mana of any color.

Exploration

You may play an additional land on each of your turns.

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Simian Spirit Guide

Exile Simian Spirit Guide from your hand: Add {R}.

City of Traitors

When you play another land, sacrifice City of Traitors.
{T}: Add {C}{C}.

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Colossal Dreadmaw

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Castle Garenbrig

Castle Garenbrig enters tapped unless you control a Forest.
{T}: Add {G}.
{2}{G}{G}, {T}: Add six {G}. Spend this mana only to cast creature spells or activate abilities of creatures.