Moon Heron

Boneyard Wurm

Boneyard Wurm's power and toughness are each equal to the number of creature cards in your graveyard.

Splinterfright

Trample
Splinterfright's power and toughness are each equal to the number of creature cards in your graveyard.
At the beginning of your upkeep, mill two cards. (Put the top two cards of your library into your graveyard.)

Aether Adept

When this creature enters, return target creature to its owner's hand.

Island

Brindle Boar

Sacrifice this creature: You gain 4 life.

Gnaw to the Bone

You gain 2 life for each creature card in your graveyard.
Flashback {2}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Chasm Drake

Flying
Whenever this creature attacks, target creature you control gains flying until end of turn.

Grim Flowering

Draw a card for each creature card in your graveyard.

Hollowhenge Beast

Ghoultree

This spell costs {1} less to cast for each creature card in your graveyard.

Ambush Viper

Executioner's Hood

Equipped creature has intimidate. (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Wreath of Geists

Enchant creature
Enchanted creature gets +X/+X, where X is the number of creature cards in your graveyard.

Mulch

Reveal the top four cards of your library. Put all land cards revealed this way into your hand and the rest into your graveyard.

Tracker's Instincts

Reveal the top four cards of your library. Put a creature card from among them into your hand and the rest into your graveyard.
Flashback {2}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Dawntreader Elk

{G}, Sacrifice this creature: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Forest

Deranged Assistant

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)

Alluring Siren

{T}: Target creature an opponent controls attacks you this turn if able.

Armored Skaab

When this creature enters, mill four cards.

Acidic Slime

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When this creature enters, destroy target artifact, enchantment, or land.

Tower Geist

Flying
When this creature enters, look at the top two cards of your library. Put one of them into your hand and the other into your graveyard.