Seton's Desire

Enchant creature
Enchanted creature gets +2/+2.
Threshold — As long as seven or more cards are in your graveyard, all creatures able to block enchanted creature do so.

Forest

Overrun

Creatures you control get +3/+3 and gain trample until end of turn. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)

Island

Nimble Mongoose

Shroud (This creature can't be the target of spells or abilities.)
Threshold — This creature gets +2/+2 as long as seven or more cards are in your graveyard.

Cephalid Looter

{T}: Target player draws a card, then discards a card.

Predict

Choose a card name, then target player mills a card. If a card with the chosen name was milled this way, you draw two cards. Otherwise, you draw a card.

Deluge

Diligent Farmhand

{1}{G}, Sacrifice this creature: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
If this card is in a graveyard, effects from spells named Muscle Burst count it as a card named Muscle Burst.

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.)

Metamorphic Wurm

Threshold — This creature gets +4/+4 as long as seven or more cards are in your graveyard.

Timberland Ruins

This land enters tapped.
{T}: Add {G}.
{T}, Sacrifice this land: Add one mana of any color.

Krosan Avenger

Trample
Threshold — {1}{G}: Regenerate this creature. Activate only if seven or more cards are in your graveyard.

Seafloor Debris

This land enters tapped.
{T}: Add {U}.
{T}, Sacrifice this land: Add one mana of any color.

Muscle Burst

Target creature gets +X/+X until end of turn, where X is 3 plus the number of cards named Muscle Burst in all graveyards.

Springing Tiger

Threshold — This creature gets +2/+2 as long as seven or more cards are in your graveyard.

Roar of the Wurm

Create a 6/6 green Wurm creature token.
Flashback {3}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Stone-Tongue Basilisk

Whenever this creature deals combat damage to a creature, destroy that creature at end of combat.
Threshold — As long as seven or more cards are in your graveyard, all creatures able to block this creature do so.

Ivy Elemental

This creature enters with X +1/+1 counters on it.

Werebear

{T}: Add {G}.
Threshold — This creature gets +3/+3 as long as seven or more cards are in your graveyard.

Repel

Put target creature on top of its owner's library.

Twigwalker

{1}{G}, Sacrifice this creature: Two target creatures each get +2/+2 until end of turn.

Careful Study

Peek

Look at target player's hand.
Draw a card.

Wild Mongrel

Discard a card: This creature gets +1/+1 and becomes the color of your choice until end of turn.

Crashing Centaur

{G}, Discard a card: This creature gains trample until end of turn.
Threshold — As long as seven or more cards are in your graveyard, this creature gets +2/+2 and has shroud. (It can't be the target of spells or abilities.)