Maelstrom Wanderer

Creatures you control have haste.
Cascade, cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order. Then do it again.)

Brackwater Elemental

When Brackwater Elemental attacks or blocks, sacrifice it at the beginning of the next end step.
Unearth (: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Duplicant

Imprint — When Duplicant enters the battlefield, you may exile target nontoken creature.
As long as a card exiled with Duplicant is a creature card, Duplicant has the power, toughness, and creature types of the last creature card exiled with Duplicant. It’s still a Shapeshifter.

Blightning

Blightning deals 3 damage to target player or planeswalker. That player or that planeswalker’s controller discards two cards.

Relentless Rats

Relentless Rats gets +1/+1 for each other creature on the battlefield named Relentless Rats.
A deck can have any number of cards named Relentless Rats.

Duplicant

Imprint — When Duplicant enters the battlefield, you may exile target nontoken creature.
As long as a card exiled with Duplicant is a creature card, Duplicant has the power, toughness, and creature types of the last creature card exiled with Duplicant. It’s still a Shapeshifter.

Festering Goblin

When Festering Goblin dies, target creature gets -1/-1 until end of turn.

My Undead Horde Awakens

(An ongoing scheme remains face up until it’s abandoned.)
At the beginning of your end step, you may put target creature card from an opponent’s graveyard onto the battlefield under your control.
When a creature put onto the battlefield with this scheme dies, abandon this scheme.

Relentless Rats

Relentless Rats gets +1/+1 for each other creature on the battlefield named Relentless Rats.
A deck can have any number of cards named Relentless Rats.

Aether Figment

Kicker (You may pay an additional as you cast this spell.)
Aether Figment can’t be blocked.
If Aether Figment was kicked, it enters the battlefield with two +1/+1 counters on it.

Soulless One

Soulless One’s power and toughness are each equal to the number of Zombies on the battlefield plus the number of Zombie cards in all graveyards.

Festering Goblin

When Festering Goblin dies, target creature gets -1/-1 until end of turn.

Entangling Vines

Enchant tapped creature
Enchanted creature doesn’t untap during its controller’s untap step.

Relentless Rats

Relentless Rats gets +1/+1 for each other creature on the battlefield named Relentless Rats.
A deck can have any number of cards named Relentless Rats.

Identity Crisis

Exile all cards from target player’s hand and graveyard.

Necromancer’s Covenant

When Necromancer’s Covenant enters the battlefield, exile all creature cards from target player’s graveyard, then create a 2/2 black Zombie creature token for each card exiled this way.
Zombies you control have lifelink.

Demonic Dread

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order.)
Target creature can’t block this turn.

Brackwater Elemental

When Brackwater Elemental attacks or blocks, sacrifice it at the beginning of the next end step.
Unearth (: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Terminate

Destroy target creature. It can’t be regenerated.

Rise from the Grave

Put target creature card from a graveyard onto the battlefield under your control. That creature is a black Zombie in addition to its other colors and types.

Merrow Reejerey

Other Merfolk creatures you control get +1/+1.
Whenever you cast a Merfolk spell, you may tap or untap target permanent.

Resounding Scream

Target player discards a card at random.
Cycling (, Discard this card: Draw a card.)
When you cycle Resounding Scream, target player discards two cards at random.