Prowler's Helm

Equipped creature can't be blocked except by Walls.
Equip {2}

Despair

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Until end of turn, creatures you control gain menace and "Whenever this creature deals combat damage to a player, that player discards a card."

Driven

Until end of turn, creatures you control gain trample and "Whenever this creature deals combat damage to a player, draw a card."

Driven // Despair

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Necroskitter

Wither (This deals damage to creatures in the form of -1/-1 counters.)
Whenever a creature an opponent controls with a -1/-1 counter on it dies, you may return that card to the battlefield under your control.

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.

Lethal Sting

As an additional cost to cast this spell, put a -1/-1 counter on a creature you control.
Destroy target creature.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Nest of Scarabs

Whenever you put one or more -1/-1 counters on a creature, create that many 1/1 black Insect creature tokens.

Wrap in Vigor

Decimator Beetle

When Decimator Beetle enters, put a -1/-1 counter on target creature you control.
Whenever Decimator Beetle attacks, remove a -1/-1 counter from target creature you control and put a -1/-1 counter on up to one target creature defending player controls.

Forgotten Ancient

Whenever a player casts a spell, you may put a +1/+1 counter on Forgotten Ancient.
At the beginning of your upkeep, you may move any number of +1/+1 counters from Forgotten Ancient onto other creatures.

Bastion of Remembrance

When Bastion of Remembrance enters, create a 1/1 white Human Soldier creature token.
Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.

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.

Exemplar of Strength

When Exemplar of Strength enters, put three -1/-1 counters on target creature you control.
Whenever Exemplar of Strength attacks, remove a -1/-1 counter from it. If you do, you gain 1 life.

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.

Generous Patron

When Generous Patron enters, support 2. (Put a +1/+1 counter on each of up to two other target creatures.)
Whenever you put one or more counters on a creature you don't control, draw a card.

Serrated Biskelion

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

Falkenrath Noble

Flying
Whenever Falkenrath Noble or another creature dies, target player loses 1 life and you gain 1 life.

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Nesting Grounds

{T}: Add {C}.
{1}, {T}: Move a counter from target permanent you control onto another target permanent. Activate only as a sorcery.

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.

Skinrender

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

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

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.

Sakura-Tribe Elder

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Second Harvest

For each token you control, create a token that's a copy of that permanent.

Incremental Blight

Put a -1/-1 counter on target creature, two -1/-1 counters on another target creature, and three -1/-1 counters on a third target creature.

Golgari Signet

Poison-Tip Archer

Reach (This creature can block creatures with flying.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Whenever another creature dies, each opponent loses 1 life.

Channeler Initiate

When Channeler Initiate enters, put three -1/-1 counters on target creature you control.
{T}, Remove a -1/-1 counter from Channeler Initiate: Add one mana of any color.

Rogue's Passage

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

Flourishing Defenses

Whenever a -1/-1 counter is put on a creature, you may create a 1/1 green Elf Warrior creature token.

Phyrexian Reclamation

{1}{B}, Pay 2 life: Return target creature card from your graveyard to your hand.

Forest

Soul Snuffers

When Soul Snuffers enters, put a -1/-1 counter on each creature.

Crumbling Ashes

At the beginning of your upkeep, destroy target creature with a -1/-1 counter on it.

Stinging Shot

Put three -1/-1 counters on target creature with flying.
Cycling {2} ({2}, Discard this card: Draw a card.)

Grim Poppet

Grim Poppet enters with three -1/-1 counters on it.
Remove a -1/-1 counter from Grim Poppet: Put a -1/-1 counter on another target creature.

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Vraska, Swarm's Eminence

Whenever a creature you control with deathtouch deals damage to a player or planeswalker, put a +1/+1 counter on that creature.
−2: Create a 1/1 black Assassin creature token with deathtouch and "Whenever this creature deals damage to a planeswalker, destroy that planeswalker."

Festering Mummy

When Festering Mummy dies, you may put a -1/-1 counter on target creature.

Priest of Forgotten Gods

{T}, Sacrifice two other creatures: Any number of target players each lose 2 life and sacrifice a creature. You add {B}{B} and draw a card.

Cinderhaze Wretch

{T}: Target player discards a card. Activate only during your turn.
Put a -1/-1 counter on Cinderhaze Wretch: Untap Cinderhaze Wretch.

Thunderfoot Baloth

Trample
Lieutenant — As long as you control your commander, Thunderfoot Baloth gets +2/+2 and other creatures you control get +2/+2 and have trample.

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.)

Nature's Claim

Destroy target artifact or enchantment. Its controller gains 4 life.

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.

Devoted Druid

{T}: Add {G}.
Put a -1/-1 counter on Devoted Druid: Untap Devoted Druid.

Defiant Greatmaw

When Defiant Greatmaw enters, put two -1/-1 counters on target creature you control.
Whenever you put one or more -1/-1 counters on Defiant Greatmaw, remove a -1/-1 counter from another target creature you control.

Sadistic Hypnotist

Sacrifice a creature: Target player discards two cards. Activate only as a sorcery.

Golgari Rot Farm

Golgari Rot Farm enters tapped.
When Golgari Rot Farm enters, return a land you control to its owner's hand.
{T}: Add {B}{G}.

Torment of Venom

Put three -1/-1 counters on target creature. Its controller loses 3 life unless they sacrifice another nonland permanent or discards a card.

Obelisk Spider

Reach
Whenever Obelisk Spider deals combat damage to a creature, put a -1/-1 counter on that creature.
Whenever you put one or more -1/-1 counters on a creature, each opponent loses 1 life and you gain 1 life.

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.

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.

Corrosive Mentor

Black creatures you control have wither. (They deal damage to creatures in the form of -1/-1 counters.)

Tainted Wood

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

Blowfly Infestation

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

Shambling Swarm

When Shambling Swarm dies, distribute three -1/-1 counters among one, two, or three target creatures. For each -1/-1 counter you put on a creature this way, remove a -1/-1 counter from that creature at the beginning of the next end step.

Victimize

Choose two target creature cards in your graveyard. Sacrifice a creature. If you do, return the chosen cards to the battlefield tapped.

Moldervine Reclamation

Whenever a creature you control dies, you gain 1 life and draw a card.

Fevered Convulsions

{2}{B}{B}: Put a -1/-1 counter on target creature.

Swamp

Splendid Agony

Distribute two -1/-1 counters among one or two target creatures.

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Overrun

Creatures you control get +3/+3 and gain trample until end of turn.

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.)

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.

Vhati il-Dal

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

Ivy Lane Denizen

Whenever another green creature you control enters, put a +1/+1 counter on target creature.

Read the Bones

Scry 2, then draw two cards. You lose 2 life.

Oran-Rief, the Vastwood

Oran-Rief, the Vastwood enters tapped.
{T}: Add {G}.
{T}: Put a +1/+1 counter on each green creature that entered this turn.

The Ozolith

Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith.
At the beginning of combat on your turn, if The Ozolith has counters on it, you may move all counters from The Ozolith onto target creature.