Flashfreeze

Acidic Slime

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When Acidic Slime enters the battlefield, destroy target artifact, enchantment, or land.

Roaring Primadox

At the beginning of your upkeep, return a creature you control to its owner's hand.

Forest

Negate

Clinging Mists

Prevent all combat damage that would be dealt this turn.
Fateful hour — If you have 5 or less life, tap all attacking creatures. Those creatures don't untap during their controller's next untap step.

Frost Breath

Tap up to two target creatures. Those creatures don't untap during their controller's next untap step.

Coiling Oracle

When Coiling Oracle enters the battlefield, reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put that card into your hand.

Augur of Bolas

When Augur of Bolas enters the battlefield, look at the top three cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Simic Guildgate

Simic Guildgate enters the battlefield tapped.
{T}: Add {G} or {U}.

Somberwald Stag

When Somberwald Stag enters the battlefield, you may have it fight target creature you don't control.

Species Gorger

Snake of the Golden Grove

Tribute 3 (As this creature enters the battlefield, an opponent of your choice may put three +1/+1 counters on it.)
When Snake of the Golden Grove enters the battlefield, if tribute wasn't paid, you gain 4 life.

Riverwise Augur

When Riverwise Augur enters the battlefield, draw three cards, then put two cards from your hand on top of your library in any order.

Ixalli's Diviner

When Ixalli's Diviner enters the battlefield, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Island

Icy Manipulator

{1}, {T}: Tap target artifact, creature, or land.

Slippery Scoundrel

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
As long as you have the city's blessing, Slippery Scoundrel has hexproof and can't be blocked.

Giant Growth

Target creature gets +3/+3 until end of turn.

Sailor of Means

When Sailor of Means enters the battlefield, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Thornwood Falls

Thornwood Falls enters the battlefield tapped.
When Thornwood Falls enters the battlefield, you gain 1 life.
{T}: Add {G} or {U}.

Divination

Nest Invader

When Nest Invader enters the battlefield, create a 0/1 colorless Eldrazi Spawn creature token. It has "Sacrifice this creature: Add {C}."

Foresee

Angler Drake

Flying
When Angler Drake enters the battlefield, you may return target creature to its owner's hand.

Atzocan Archer

Reach
When Atzocan Archer enters the battlefield, you may have it fight another target creature. (Each deals damage equal to its power to the other.)