Ghalta, Primal Hunger

This spell costs {X} less to cast, where X is the total power of creatures you control.
Trample

Radiant Fountain

When Radiant Fountain enters, you gain 2 life.
{T}: Add {C}.

Voracious Wurm

Voracious Wurm enters with X +1/+1 counters on it, where X is the amount of life you've gained this turn.

Forest

Tormod's Crypt

{T}, Sacrifice Tormod's Crypt: Exile target player's graveyard.

Natural State

Destroy target artifact or enchantment with mana value 3 or less.

Royal Treatment

Target creature you control gains hexproof until end of turn. Create a Royal Role token attached to that creature. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1 and has ward {1}.)

Not of This World

Counter target spell or ability that targets a permanent you control.
This spell costs {7} less to cast if it targets a spell or ability that targets a creature you control with power 7 or greater.

Nourishing Shoal

You may exile a green card with mana value X from your hand rather than pay this spell's mana cost.
You gain X life.

Titanoth Rex

Trample
Cycling {1}{G} ({1}{G}, Discard this card: Draw a card.)
When you cycle Titanoth Rex, put a trample counter on target creature you control.

Chancellor of the Tangle

You may reveal this card from your opening hand. If you do, at the beginning of your first main phase of the game, add {G}.
Vigilance, reach

Rancor

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

Serum Powder

{T}: Add {C}.
Any time you could mulligan and Serum Powder is in your hand, you may exile all the cards from your hand, then draw that many cards. (You can do this in addition to taking mulligans.)

Fight Rigging

Hideaway 5 (When this enchantment enters, look at the top five cards of your library, exile one face down, then put the rest on the bottom in a random order.)
At the beginning of combat on your turn, put a +1/+1 counter on target creature you control. Then if you control a creature with power 7 or greater, you may play the exiled card without paying its mana cost.