Archfiend of Ifnir

Flying
Whenever you cycle or discard another card, put a -1/-1 counter on each creature your opponents control.
Cycling {2} ({2}, Discard this card: Draw a card.)

Fallen Askari

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)
Fallen Askari can't block.

Grim Affliction

Put a -1/-1 counter on target creature, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Golgari Cluestone

{T}: Add {B} or {G}.
{B}{G}, {T}, Sacrifice Golgari Cluestone: Draw a card.

Sachi, Daughter of Seshiro

Other Snake creatures you control get +0/+1.
Shamans you control have "{T}: Add {G}{G}."

Flensermite

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Hapatra's Mark

Target creature you control gains hexproof until end of turn. Remove all -1/-1 counters from it. (A creature with hexproof can't be the target of spells or abilities your opponents control.)

Aboroth

Cumulative upkeep—Put a -1/-1 counter on Aboroth. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

Trigon of Corruption

Trigon of Corruption enters with three charge counters on it.
{B}{B}, {T}: Put a charge counter on Trigon of Corruption.
{2}, {T}, Remove a charge counter from Trigon of Corruption: Put a -1/-1 counter on target creature.

Oona's Gatewarden

Defender, flying
Wither (This deals damage to creatures in the form of -1/-1 counters.)

Phyrexian Denouncer

{T}, Sacrifice Phyrexian Denouncer: Target creature gets -1/-1 until end of turn.

Noxious Hatchling

Noxious Hatchling enters with four -1/-1 counters on it.
Wither (This deals damage to creatures in the form of -1/-1 counters.)
Whenever you cast a black spell, remove a -1/-1 counter from Noxious Hatchling.
Whenever you cast a green spell, remove a -1/-1 counter from Noxious Hatchling.

Blazethorn Scarecrow

Blazethorn Scarecrow has haste as long as you control a red creature.
Blazethorn Scarecrow has wither as long as you control a green creature. (It deals damage to creatures in the form of -1/-1 counters.)

Dust

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Exile any number of target creatures that have -1/-1 counters on them.

Grind

Put a -1/-1 counter on each of up to two target creatures.

Grind // Dust

Afflict

Target creature gets -1/-1 until end of turn.
Draw a card.

Palace Siege

As Palace Siege enters, choose Khans or Dragons.
• Khans — At the beginning of your upkeep, return target creature card from your graveyard to your hand.
• Dragons — At the beginning of your upkeep, each opponent loses 2 life and you gain 2 life.

Hand of the Praetors

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Other creatures you control with infect get +1/+1.
Whenever you cast a creature spell with infect, target player gets a poison counter.

Jabari's Banner

{1}, {T}: Target creature gains flanking until end of turn. (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)

Ancestral Vengeance

Enchant creature
When Ancestral Vengeance enters, put a +1/+1 counter on target creature you control.
Enchanted creature gets -1/-1.

Blight Sickle

Equipped creature gets +1/+0 and has wither. (It deals damage to creatures in the form of -1/-1 counters.)
Equip {2}

Woodlurker Mimic

Whenever you cast a spell that's both black and green, Woodlurker Mimic has base power and toughness 4/5 until end of turn and gains wither until end of turn. (It deals damage to creatures in the form of -1/-1 counters.)

Cruel Sadist

{B}, {T}, Pay 1 life: Put a +1/+1 counter on Cruel Sadist.
{2}{B}, {T}, Remove X +1/+1 counters from Cruel Sadist: It deals X damage to target creature.

Tower Above

({2/G} can be paid with any two mana or with {G}. This card's mana value is 6.)
Until end of turn, target creature gets +4/+4 and gains trample, wither, and "When this creature attacks, target creature blocks it this turn if able." (It deals damage to creatures in the form of -1/-1 counters.)

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Raise Dead

Return target creature card from your graveyard to your hand.

Parallel Evolution

For each creature token on the battlefield, its controller creates a token that's a copy of that creature.
Flashback {4}{G}{G}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Survivors' Encampment

{T}: Add {C}.
{T}, Tap an untapped creature you control: Add one mana of any color.

Phyrexian Swarmlord

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
At the beginning of your upkeep, create a 1/1 green Phyrexian Insect creature token with infect for each poison counter your opponents have.

Demon of Catastrophes

As an additional cost to cast this spell, sacrifice a creature.
Flying, trample

Mutilate

All creatures get -1/-1 until end of turn for each Swamp you control.

Cadaverous Knight

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)
{1}{B}{B}: Regenerate Cadaverous Knight.

Scuzzback Marauders

Trample
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Serrated Arrows

Serrated Arrows enters with three arrowhead counters on it.
At the beginning of your upkeep, if there are no arrowhead counters on Serrated Arrows, sacrifice it.
{T}, Remove an arrowhead counter from Serrated Arrows: Put a -1/-1 counter on target creature.

Twinblade Slasher

Wither (This deals damage to creatures in the form of -1/-1 counters.)
{1}{G}: Twinblade Slasher gets +2/+2 until end of turn. Activate only once each turn.

Jolrael's Centaur

Shroud (This creature can't be the target of spells or abilities.)
Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)

Kothophed, Soul Hoarder

Flying
Whenever a permanent owned by another player is put into a graveyard from the battlefield, you draw a card and you lose 1 life.

Tangle Angler

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{G}: Target creature blocks Tangle Angler this turn if able.

Carnifex Demon

Flying
Carnifex Demon enters with two -1/-1 counters on it.
{B}, Remove a -1/-1 counter from Carnifex Demon: Put a -1/-1 counter on each other creature.

Cystbearer

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Vhati il-Dal

{T}: Until end of turn, target creature has base power 1 or base toughness 1.

Hapatra, Vizier of Poisons

Whenever Hapatra, Vizier of Poisons deals combat damage to a player, you may put a -1/-1 counter on target creature.
Whenever you put one or more -1/-1 counters on a creature, create a 1/1 green Snake creature token with deathtouch.

Banewhip Punisher

When Banewhip Punisher enters, you may put a -1/-1 counter on target creature.
{B}, Sacrifice Banewhip Punisher: Destroy target creature that has a -1/-1 counter on it.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Carrion Call

Create two 1/1 green Phyrexian Insect creature tokens with infect. (They deal damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Septic Rats

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever Septic Rats attacks, if defending player is poisoned, it gets +1/+1 until end of turn.

Kodama's Reach

Juvenile Gloomwidow

Reach (This creature can block creatures with flying.)
Wither (This deals damage to creatures in the form of -1/-1 counters.)

Black Sun's Zenith

Put X -1/-1 counters on each creature. Shuffle Black Sun's Zenith into its owner's library.

Soulstinger

When Soulstinger enters, put two -1/-1 counters on target creature you control.
When Soulstinger dies, you may put a -1/-1 counter on target creature for each -1/-1 counter on Soulstinger.

Rendclaw Trow

Wither (This deals damage to creatures in the form of -1/-1 counters.)
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Contagion Clasp

When Contagion Clasp enters, put a -1/-1 counter on target creature.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Ammit Eternal

Afflict 3 (Whenever this creature becomes blocked, defending player loses 3 life.)
Whenever an opponent casts a spell, put a -1/-1 counter on Ammit Eternal.
Whenever Ammit Eternal deals combat damage to a player, remove all -1/-1 counters from it.

Putrefy

Destroy target artifact or creature. It can't be regenerated.

Winding Constrictor

If one or more counters would be put on an artifact or creature you control, that many plus one of each of those kinds of counters are put on that permanent instead.
If you would get one or more counters, you get that many plus one of each of those kinds of counters instead.

Rot Wolf

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever a creature dealt damage by Rot Wolf this turn dies, you may draw a card.

Contagious Nim

Phyrexian Digester

Ichor Rats

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When Ichor Rats enters, each player gets a poison counter.

Serrated Biskelion

{T}: Put a -1/-1 counter on Serrated Biskelion and a -1/-1 counter on target creature.

Blowfly Infestation

Whenever a creature dies, if it had a -1/-1 counter on it, put a -1/-1 counter on target creature.

Sickle Ripper

Wither (This deals damage to creatures in the form of -1/-1 counters.)

Blightwidow

Reach (This creature can block creatures with flying.)
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Wickerbough Elder

Wickerbough Elder enters with a -1/-1 counter on it.
{G}, Remove a -1/-1 counter from Wickerbough Elder: Destroy target artifact or enchantment.

Manalith

Baleful Ammit

Lifelink
When Baleful Ammit enters, put a -1/-1 counter on target creature you control.

Fists of the Demigod

Enchant creature
As long as enchanted creature is black, it gets +1/+1 and has wither. (It deals damage to creatures in the form of -1/-1 counters.)
As long as enchanted creature is red, it gets +1/+1 and has first strike.

Urban Burgeoning

Enchant land
Enchanted land has "Untap this land during each other player's untap step."

Viridian Betrayers

Viridian Betrayers has infect as long as an opponent is poisoned. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Skinrender

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

Elvish Rejuvenator

When Elvish Rejuvenator enters, look at the top five cards of your library. You may put a land card from among them onto the battlefield tapped. Put the rest on the bottom of your library in a random order.