Wreath of Geists

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

Boneyard Wurm

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

Armored Skaab

When Armored Skaab enters, mill four cards.

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.)

Dawntreader Elk

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

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.

Deranged Assistant

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

Ambush Viper

Tower Geist

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

Moon Heron

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.)

Acidic Slime

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

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.)

Chasm Drake

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

Ghoultree

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

Aether Adept

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

Grim Flowering

Draw a card for each creature card in your graveyard.

Hollowhenge Beast

Forest

Brindle Boar

Alluring Siren

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