Swamp

Jungle Hollow

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {G}.

Kessig Recluse

Reach (This creature can block creatures with flying.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Splendid Agony

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

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.

Trial of Ambition

When Trial of Ambition enters, target opponent sacrifices a creature of their choice.
When a Cartouche you control enters, return Trial of Ambition to its owner's hand.

Supernatural Stamina

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control."

Nest of Scarabs

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

Cartouche of Ambition

Enchant creature you control
When Cartouche of Ambition enters, you may put a -1/-1 counter on target creature.
Enchanted creature gets +1/+1 and has lifelink.

Oashra Cultivator

{2}{G}, {T}, Sacrifice Oashra Cultivator: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

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.

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.

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.

Festering Mummy

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

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.

Foul Orchard

Foul Orchard enters tapped.
{T}: Add {B} or {G}.

Liliana's Influence

Put a -1/-1 counter on each creature you don't control. You may search your library and/or graveyard for a card named Liliana, Death Wielder, reveal it, and put it into your hand. If you search your library this way, shuffle.

Crocodile of the Crossing

Haste
When Crocodile of the Crossing enters, put a -1/-1 counter on target creature you control.

Cartouche of Strength

Enchant creature you control
When Cartouche of Strength enters, you may have enchanted creature fight target creature an opponent controls. (Each deals damage equal to its power to the other.)
Enchanted creature gets +1/+1 and has trample.

Forest

Baleful Ammit

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

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.

Liliana, Death Wielder

+2: Put a -1/-1 counter on up to one target creature.
−3: Destroy target creature with a -1/-1 counter on it.
−10: Return all creature cards from your graveyard to the battlefield.

Shed Weakness

Target creature gets +2/+2 until end of turn. You may remove a -1/-1 counter from it.