Nether Shadow

Haste
At the beginning of your upkeep, if Nether Shadow is in your graveyard with three or more creature cards above it, you may put Nether Shadow onto the battlefield.

Mineshaft Spider

Reach
When Mineshaft Spider enters, you may mill two cards. (You may put the top two cards of your library into your graveyard.)

Treasure Chest

{4}, Sacrifice Treasure Chest: Roll a d20.
1 | Trapped! — You lose 3 life.
2—9 | Create five Treasure tokens.
10—19 | You gain 3 life and draw three cards.
20 | Search your library for a card. If it's an artifact card, you may put it onto the battlefield. Otherwise, put that card into your hand. Then shuffle.

Nether Spirit

At the beginning of your upkeep, if Nether Spirit is the only creature card in your graveyard, you may return Nether Spirit to the battlefield.

Potion of Healing

When Potion of Healing enters, draw a card.
{W}, {T}, Sacrifice Potion of Healing: You gain 3 life.

Nether Void

Whenever a player casts a spell, counter it unless that player pays {3}.

Iron Golem

Vigilance
Iron Golem attacks or blocks each combat if able.

Vengeful Creeper

Disguise {5}{G} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)
When Vengeful Creeper is turned face up, destroy target artifact or enchantment an opponent controls.

Nether Horror

Diamond Pick-Axe

Indestructible (Effects that say "destroy" don't destroy this artifact.)
Equipped creature gets +1/+1 and has "Whenever this creature attacks, create a Treasure token." (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Equip {2}