Spark Reaper

{3}, Sacrifice a creature or planeswalker: You gain 1 life and draw a card.

Swamp

Stitched Assistant

Exploit (When this creature enters, you may sacrifice a creature.)
When Stitched Assistant exploits a creature, scry 1, then draw a card. (To scry 1, look at the top card of your library, then you may put that card on the bottom.)

Skinrender

When Skinrender enters, put three -1/-1 counters on target creature.

Island

Rot-Tide Gargantua

Exploit (When this creature enters, you may sacrifice a creature.)
When Rot-Tide Gargantua exploits a creature, each opponent sacrifices a creature of their choice.

Rank Officer

When Rank Officer enters, you may discard a card. If you do, create a 2/2 black Zombie creature token.
{1}{B}, {T}, Exile a creature card from your graveyard: Each opponent loses 2 life.

Diver Skaab

Exploit (When this creature enters, you may sacrifice a creature.)
When Diver Skaab exploits a creature, target creature's owner puts it on their choice of the top or bottom of their library.

Mindleech Ghoul

Exploit (When this creature enters, you may sacrifice a creature.)
When Mindleech Ghoul exploits a creature, each opponent exiles a card from their hand.

Corpse Cobble

As an additional cost to cast this spell, sacrifice any number of creatures.
Create an X/X blue and black Zombie creature token with menace, where X is the total power of the sacrificed creatures.
Flashback {3}{U}{B} (You may cast this card from your graveyard for its flashback cost and any additional costs. Then exile it.)

Skaab Wrangler

Tap three untapped creatures you control: Tap target creature.

Vivisection

As an additional cost to cast this spell, sacrifice a creature.
Draw three cards.

Toxic Abomination

When Toxic Abomination enters, you lose 2 life.

Gravedigger

When Gravedigger enters, you may return target creature card from your graveyard to your hand.

Waterfront District

Waterfront District enters tapped.
{T}: Add {U} or {B}.
{2}{U}{B}, {T}, Sacrifice Waterfront District: Draw a card.

Skull Skaab

Exploit (When this creature enters, you may sacrifice a creature.)
Whenever a creature you control exploits a nontoken creature, create a 2/2 black Zombie creature token.

Bone Splinters

As an additional cost to cast this spell, sacrifice a creature.
Destroy target creature.