Swamp

Crypt Rats

{X}: Crypt Rats deals X damage to each creature and each player. Spend only black mana on X.

Rancid Earth

Destroy target land.
Threshold — If seven or more cards are in your graveyard, instead destroy that land and Rancid Earth deals 1 damage to each creature and each player.

Witch's Cottage

({T}: Add {B}.)
Witch's Cottage enters tapped unless you control three or more other Swamps.
When Witch's Cottage enters untapped, you may put target creature card from your graveyard on top of your library.

Geth's Verdict

Target player sacrifices a creature of their choice and loses 1 life.

Choking Sands

Destroy target non-Swamp land. If that land was nonbasic, Choking Sands deals 2 damage to the land's controller.

Unexpected Fangs

Put a +1/+1 counter and a lifelink counter on target creature.

Nihil Spellbomb

{T}, Sacrifice Nihil Spellbomb: Exile target player's graveyard.
When Nihil Spellbomb is put into a graveyard from the battlefield, you may pay {B}. If you do, draw a card.

Suffocating Fumes

Creatures your opponents control get -1/-1 until end of turn.
Cycling {2} ({2}, Discard this card: Draw a card.)

Chainer's Edict

Target player sacrifices a creature of their choice.
Flashback {5}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Cast Down

Defile

Target creature gets -1/-1 until end of turn for each Swamp you control.

Icequake

Destroy target land. If that land was a snow land, Icequake deals 1 damage to that land's controller.

Gurmag Angler

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)

Okiba-Gang Shinobi

Ninjutsu {3}{B} ({3}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Okiba-Gang Shinobi deals combat damage to a player, that player discards two cards.

Snow-Covered Swamp

Sign in Blood

Target player draws two cards and loses 2 life.

Dark Ritual

Thorn of the Black Rose

Deathtouch
When Thorn of the Black Rose enters, you become the monarch.

Chittering Rats

When Chittering Rats enters, target opponent puts a card from their hand on top of their library.

Peat Bog

Peat Bog enters tapped with two depletion counters on it.
{T}, Remove a depletion counter from Peat Bog: Add {B}{B}. If there are no depletion counters on Peat Bog, sacrifice it.