Ice-Fang Coatl

Flash
Flying
When this creature enters, draw a card.
This creature has deathtouch as long as you control at least three other snow permanents.

Cavern Harpy

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

Green Sun's Zenith

Search your library for a green creature card with mana value X or less, put it onto the battlefield, then shuffle. Shuffle Green Sun's Zenith into its owner's library.

Leovold, Emissary of Trest

Each opponent can't draw more than one card each turn.
Whenever you or a permanent you control becomes the target of a spell or ability an opponent controls, you may draw a card.

Baleful Strix

Flying, deathtouch
When this creature enters, draw a card.

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.)

Aluren

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

Grist, the Hunger Tide

As long as Grist 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.

Acererak the Archlich

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