Cavern Harpy

Flying
When Cavern Harpy enters, return a blue or black creature you control to its owner's hand.
Pay 1 life: Return Cavern Harpy to its owner's hand.

Bayou

Ice-Fang Coatl

Flash
Flying
When Ice-Fang Coatl enters, draw a card.
Ice-Fang Coatl has deathtouch as long as you control at least three other snow permanents.

Birds of Paradise

Snuff Out

If you control a Swamp, you may pay 4 life rather than pay this spell's mana cost.
Destroy target nonblack creature. It can't be regenerated.

Baleful Strix

Flying, deathtouch
When Baleful Strix enters, draw a card.

Grist, the Hunger Tide

As long as Grist, the Hunger Tide isn't on the battlefield, it's a 1/1 Insect creature in addition to its other types.
+1: Create a 1/1 black and green Insect creature token, then mill a card. If an Insect card was milled this way, put a loyalty counter on Grist and repeat this process.
−2: You may sacrifice a creature. When you do, destroy target creature or planeswalker.
−5: Each opponent loses life equal to the number of creature cards in your graveyard.

Underground Sea

Aluren

Any player may cast creature spells with mana value 3 or less without paying their mana costs and as though they had flash.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Abrupt Decay

This spell can't be countered.
Destroy target nonland permanent with mana value 3 or less.

Verdant Catacombs

{T}, Pay 1 life, Sacrifice Verdant Catacombs: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Flusterstorm

Counter target instant or sorcery spell unless its controller pays {1}.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Acererak the Archlich

When Acererak the Archlich enters, if you haven't completed Tomb of Annihilation, return Acererak the Archlich to its owner's hand and venture into the dungeon.
Whenever Acererak the Archlich attacks, for each opponent, you create a 2/2 black Zombie creature token unless that player sacrifices a creature of their choice.

Tropical Island

Snow-Covered Swamp

Carpet of Flowers

At the beginning of each of your main phases, if you haven't added mana with this ability this turn, you may add X mana of any one color, where X is the number of Islands target opponent controls.

Snow-Covered Island

Misty Rainforest

{T}, Pay 1 life, Sacrifice Misty Rainforest: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

Force of Will

You may pay 1 life and exile a blue card from your hand rather than pay this spell's mana cost.
Counter target spell.

Force of Negation

If it's not your turn, you may exile a blue card from your hand rather than pay this spell's mana cost.
Counter target noncreature spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Endurance

Flash
Reach
When Endurance enters, up to one target player puts all the cards from their graveyard on the bottom of their library in a random order.
Evoke—Exile a green card from your hand.

Plague Engineer

Deathtouch
As Plague Engineer enters, choose a creature type.
Creatures of the chosen type your opponents control get -1/-1.

Seeds of Innocence

Destroy all artifacts. They can't be regenerated. The controller of each of those artifacts gains life equal to its mana value.

Snow-Covered Forest

Uro, Titan of Nature's Wrath

When Uro enters, sacrifice it unless it escaped.
Whenever Uro enters or attacks, you gain 3 life and draw a card, then you may put a land card from your hand onto the battlefield.
Escape—{G}{G}{U}{U}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)