Swamp

Deathgazer

Whenever Deathgazer blocks or becomes blocked by a nonblack creature, destroy that creature at end of combat.

Phyrexian Gargantua

When Phyrexian Gargantua enters, you draw two cards and you lose 2 life.

Phyrexian Totem

{T}: Add {B}.
{2}{B}: Phyrexian Totem becomes a 5/5 black Phyrexian Horror artifact creature with trample until end of turn.
Whenever Phyrexian Totem is dealt damage, if it's a creature, sacrifice that many permanents.

Gravedigger

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

Sengir Vampire

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever a creature dealt damage by Sengir Vampire this turn dies, put a +1/+1 counter on Sengir Vampire.

Nightmare

Flying (This creature can't be blocked except by creatures with flying or reach.)
Nightmare's power and toughness are each equal to the number of Swamps you control.

Demon's Horn

Whenever a player casts a black spell, you may gain 1 life.

Drudge Skeletons

{B}: Regenerate Drudge Skeletons. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Highway Robber

When Highway Robber enters, target opponent loses 2 life and you gain 2 life.

Nekrataal

First strike
When Nekrataal enters, destroy target nonartifact, nonblack creature. That creature can't be regenerated.

Tanglebloom

Consume Spirit

Spend only black mana on X.
Consume Spirit deals X damage to any target and you gain X life.

Pit Keeper

When Pit Keeper enters, if you have four or more creature cards in your graveyard, you may return target creature card from your graveyard to your hand.