Heartbeat of Spring

Whenever a player taps a land for mana, that player adds one mana of any type that land produced.

Invigorate

If you control a Forest, rather than pay this spell's mana cost, you may have an opponent gain 3 life.
Target creature gets +4/+4 until end of turn.

Eldrazi Spawn

Kozilek's Predator

When this creature enters, create two 0/1 colorless Eldrazi Spawn creature tokens. They have "Sacrifice this token: Add {C}."

Liege of the Tangle

Trample
Whenever this creature deals combat damage to a player, you may choose any number of target lands you control and put an awakening counter on each of them. Each of those lands is an 8/8 green Elemental creature for as long as it has an awakening counter on it. They're still lands.

Mana Reflection

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

Might of the Masses

Target creature gets +1/+1 until end of turn for each creature you control.

Noble Hierarch

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{T}: Add {G}, {W}, or {U}.

Reclamation Sage

When this creature enters, you may destroy target artifact or enchantment.

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.

Glint-Sleeve Artisan

Servo

Fabricate 1 (When this creature enters, put a +1/+1 counter on it or create a 1/1 colorless Servo artifact creature token.)

Skullmulcher

Devour 1 (As this creature enters, you may sacrifice any number of creatures. It enters with that many +1/+1 counters on it.)
When this creature enters, draw a card for each creature it devoured.

Sylvan Might

Target creature gets +2/+2 and gains trample until end of turn.
Flashback {2}{G}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Elephant

Terastodon

When this creature enters, you may destroy up to three target noncreature permanents. For each permanent put into a graveyard this way, its controller creates a 3/3 green Elephant creature token.

Thragtusk

Beast

When this creature enters, you gain 5 life.
When this creature leaves the battlefield, create a 3/3 green Beast creature token.

Clue

Ulvenwald Mysteries

Human Soldier

Whenever a nontoken creature you control dies, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Whenever you sacrifice a Clue, create a 1/1 white Human Soldier creature token.

Vengevine

Haste
Whenever you cast a spell, if it's the second creature spell you cast this turn, you may return this card from your graveyard to the battlefield.

Double Masters