Tainted Wood

{T}: Add {C}.
{T}: Add {B} or {G}. Activate only if you control a Swamp.

Putrid Leech

Pay 2 life: Putrid Leech gets +2/+2 until end of turn. Activate only once each turn.

Nekrataal

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

Grisly Spectacle

Destroy target nonartifact creature. Its controller mills cards equal to that creature's power.

Underworld Connections

Enchant land
Enchanted land has "{T}, Pay 1 life: Draw a card."

Mold Shambler

Kicker {1}{G} (You may pay an additional {1}{G} as you cast this spell.)
When Mold Shambler enters, if it was kicked, destroy target noncreature permanent.

Acidic Slime

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When Acidic Slime enters, destroy target artifact, enchantment, or land.

Reaper of the Wilds

Whenever another creature dies, scry 1.
{B}: Reaper of the Wilds gains deathtouch until end of turn.
{1}{G}: Reaper of the Wilds gains hexproof until end of turn.

Shadow Alley Denizen

Whenever another black creature you control enters, target creature gains intimidate until end of turn. (It can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Vinelasher Kudzu

Landfall — Whenever a land you control enters, put a +1/+1 counter on Vinelasher Kudzu.

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Ohran Viper

Whenever Ohran Viper deals combat damage to a creature, destroy that creature at end of combat.
Whenever Ohran Viper deals combat damage to a player, you may draw a card.

Stonefare Crocodile

{2}{B}: Stonefare Crocodile gains lifelink until end of turn. (Damage dealt by this creature also causes you to gain that much life.)

Forest

Corpse Traders

{2}{B}, Sacrifice a creature: Target opponent reveals their hand. You choose a card from it. That player discards that card. Activate only as a sorcery.

Spawnwrithe

Trample
Whenever Spawnwrithe deals combat damage to a player, create a token that's a copy of Spawnwrithe.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Festerhide Boar

Trample
Morbid — Festerhide Boar enters with two +1/+1 counters on it if a creature died this turn.

Consume Strength

Target creature gets +2/+2 until end of turn. Another target creature gets -2/-2 until end of turn.

Vraska the Unseen

+1: Until your next turn, whenever a creature deals combat damage to Vraska the Unseen, destroy that creature.
−3: Destroy target nonland permanent.
−7: Create three 1/1 black Assassin creature tokens with "Whenever this creature deals combat damage to a player, that player loses the game."

Wight of Precinct Six

Wight of Precinct Six gets +1/+1 for each creature card in your opponents' graveyards.

Last Kiss

Last Kiss deals 2 damage to target creature and you gain 2 life.

Death-Hood Cobra

{1}{G}: Death-Hood Cobra gains reach until end of turn.
{1}{G}: Death-Hood Cobra gains deathtouch until end of turn.

Drooling Groodion

{2}{B}{G}, Sacrifice a creature: Target creature gets +2/+2 until end of turn. Another target creature gets -2/-2 until end of turn.

Highway Robber

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

Marsh Casualties

Kicker {3} (You may pay an additional {3} as you cast this spell.)
Creatures target player controls get -1/-1 until end of turn. If this spell was kicked, those creatures get -2/-2 until end of turn instead.

Slate Street Ruffian

Whenever Slate Street Ruffian becomes blocked, defending player discards a card.

Stab Wound

Enchant creature
Enchanted creature gets -2/-2.
At the beginning of the upkeep of enchanted creature's controller, that player loses 2 life.

Gatecreeper Vine

Defender
When Gatecreeper Vine enters, you may search your library for a basic land card or a Gate card, reveal it, put it into your hand, then shuffle.

Golgari Guildgate

Golgari Guildgate enters tapped.
{T}: Add {B} or {G}.

Sadistic Augermage

When Sadistic Augermage dies, each player puts a card from their hand on top of their library.

Pulse Tracker

Whenever Pulse Tracker attacks, each opponent loses 1 life.

Tavern Swindler

{T}, Pay 3 life: Flip a coin. If you win the flip, you gain 6 life.

Oran-Rief Recluse

Kicker {2}{G} (You may pay an additional {2}{G} as you cast this spell.)
Reach (This creature can block creatures with flying.)
When Oran-Rief Recluse enters, if it was kicked, destroy target creature with flying.

Night's Whisper

River Boa

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
{G}: Regenerate River Boa.

Hypnotic Cloud

Kicker {4} (You may pay an additional {4} as you cast this spell.)
Target player discards a card. If this spell was kicked, that player discards three cards instead.