Horizon Chimera

Flash
Flying, trample
Whenever you draw a card, you gain 1 life.

Sigiled Starfish

{T}: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Ambush Viper

Pack Guardian

Flash (You may cast this spell any time you could cast an instant.)
When Pack Guardian enters, you may discard a land card. If you do, create a 2/2 green Wolf creature token.

The Reality Chip

You may look at the top card of your library any time.
As long as The Reality Chip is attached to a creature, you may play lands and cast spells from the top of your library.
Reconfigure {2}{U} ({2}{U}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Illusory Ambusher

Flash (You may cast this spell any time you could cast an instant.)
Whenever Illusory Ambusher is dealt damage, draw that many cards.

Nightpack Ambusher

Flash
Other Wolves and Werewolves you control get +1/+1.
At the beginning of your end step, if you didn't cast a spell this turn, create a 2/2 green Wolf creature token.

Sakashima's Protege

Flash
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
You may have Sakashima's Protege enter as a copy of any permanent that entered this turn.

Glademuse

Whenever a player casts a spell, if it's not their turn, that player draws a card.

Thought Sponge

Flash
Thought Sponge enters with a number of +1/+1 counters on it equal to the greatest number of cards an opponent has drawn this turn.
When Thought Sponge dies, draw cards equal to its power.

Winged Coatl

Flash (You may cast this spell any time you could cast an instant.)
Flying
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Wildborn Preserver

Flash (You may cast this spell any time you could cast an instant.)
Reach (This creature can block creatures with flying.)
Whenever another non-Human creature you control enters, you may pay {X}. When you do, put X +1/+1 counters on this creature.

Brineborn Cutthroat

Flash (You may cast this spell any time you could cast an instant.)
Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on this creature.

Archmage Emeritus

Magecraft — Whenever you cast or copy an instant or sorcery spell, draw a card.

Portal Mage

Flash
When Portal Mage enters during the declare attackers step, you may reselect which player or permanent target attacking creature is attacking. (It can't attack its controller or their permanents.)

Thryx, the Sudden Storm

Flash (You may cast this spell any time you could cast an instant.)
Flying
Spells you cast with mana value 5 or greater cost {1} less to cast and can't be countered.

Aboleth Spawn

Flash
Ward {2}
Probing Telepathy — Whenever a creature entering under an opponent's control causes a triggered ability of that creature to trigger, you may copy that ability. You may choose new targets for the copy.

Baral, Chief of Compliance

Instant and sorcery spells you cast cost {1} less to cast.
Whenever a spell or ability you control counters a spell, you may draw a card. If you do, discard a card.

Dream Eater

Flash
Flying
When Dream Eater enters, surveil 4. When you do, you may return target nonland permanent an opponent controls to its owner's hand. (To surveil 4, look at the top four cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Frilled Mystic

Flash
When Frilled Mystic enters, you may counter target spell.

Mystic Snake

Flash
When Mystic Snake enters, counter target spell.

Lictor

Flash
Pheromone Trail — When Lictor enters, if a creature entered the battlefield under an opponent's control this turn, create a 3/3 green Tyranid Warrior creature token with trample.

Cloudthresher

Flash
Reach
When Cloudthresher enters, it deals 2 damage to each creature with flying and each player.
Evoke {2}{G}{G} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Teferi, Mage of Zhalfir

Flash
Creature cards you own that aren't on the battlefield have flash.
Each opponent can cast spells only any time they could cast a sorcery.

Haze Frog

Flash (You may cast this spell any time you could cast an instant.)
When Haze Frog enters, prevent all combat damage that other creatures would deal this turn.

Plaxmanta

Flash
When Plaxmanta enters, creatures you control gain shroud until end of turn. (They can't be the targets of spells or abilities.)
When Plaxmanta enters, sacrifice it unless {G} was spent to cast it.

Fleetfeather Cockatrice

Flash (You may cast this spell any time you could cast an instant.)
Flying, deathtouch
{5}{G}{U}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)

Augur of Autumn

You may look at the top card of your library any time.
You may play lands from the top of your library.
Coven — As long as you control three or more creatures with different powers, you may cast creature spells from the top of your library.

Yeva, Nature's Herald

Flash (You may cast this spell any time you could cast an instant.)
You may cast green creature spells as though they had flash.

Snapping Sailback

Flash
Enrage — Whenever Snapping Sailback is dealt damage, put a +1/+1 counter on it. (It must survive the damage to get the counter.)

Gilt-Leaf Seer

{G}, {T}: Look at the top two cards of your library, then put them back in any order.

Wavebreak Hippocamp

Whenever you cast your first spell during each opponent's turn, draw a card.

Rashmi, Eternities Crafter

Whenever you cast your first spell each turn, reveal the top card of your library. You may cast it without paying its mana cost if it's a spell with lesser mana value. If you don't cast it, put it into your hand.

Stunt Double

Flash
You may have Stunt Double enter as a copy of any creature on the battlefield.

Green Slime

Flash
When Green Slime enters, counter target activated or triggered ability from an artifact or enchantment source. If a permanent's ability is countered this way, destroy that permanent.
Foretell {G} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Pearl Lake Ancient

Flash
This spell can't be countered.
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Return three lands you control to their owner's hand: Return Pearl Lake Ancient to its owner's hand.

Nissa, Sage Animist

+1: Reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put it into your hand.
−2: Create Ashaya, the Awoken World, a legendary 4/4 green Elemental creature token.
−7: Untap up to six target lands. They become 6/6 Elemental creatures. They're still lands.

Nissa, Vastwood Seer

When Nissa, Vastwood Seer enters, you may search your library for a basic Forest card, reveal it, put it into your hand, then shuffle.
Whenever a land you control enters, if you control seven or more lands, exile Nissa, then return her to the battlefield transformed under her owner's control.

Nissa, Vastwood Seer // Nissa, Sage Animist

Talrand, Sky Summoner

Whenever you cast an instant or sorcery spell, create a 2/2 blue Drake creature token with flying.

Bounding Krasis

Flash (You may cast this spell any time you could cast an instant.)
When Bounding Krasis enters, you may tap or untap target creature.

Venser, Shaper Savant

Flash (You may cast this spell any time you could cast an instant.)
When Venser, Shaper Savant enters, return target spell or permanent to its owner's hand.

Naiad of Hidden Coves

During turns other than yours, spells you cast cost {1} less to cast.

Voidmage Husher

Flash (You may cast this spell any time you could cast an instant.)
When Voidmage Husher enters, counter target activated ability. (Mana abilities can't be targeted.)
Whenever you cast a spell, you may return Voidmage Husher to its owner's hand.

Mocking Doppelganger

Flash
You may have Mocking Doppelganger enter as a copy of a creature an opponent controls, except it has "Other creatures with the same name as this creature are goaded." (They attack each combat if able and attack a player other than you if able.)

Draining Whelk

Flash
Flying
When Draining Whelk enters, counter target spell. Put X +1/+1 counters on Draining Whelk, where X is that spell's mana value.

Slippery Bogbonder

Flash
Hexproof
When Slippery Bogbonder enters, put a hexproof counter on target creature. Then move any number of counters from among creatures you control onto that creature.

Crafty Cutpurse

Flash
When Crafty Cutpurse enters, each token that would be created under an opponent's control this turn is created under your control instead.

Hullbreaker Horror

Flash
This spell can't be countered.
Whenever you cast a spell, choose up to one —
• Return target spell you don't control to its owner's hand.
• Return target nonland permanent to its owner's hand.

Nimble Obstructionist

Flash
Flying
Cycling {2}{U} ({2}{U}, Discard this card: Draw a card.)
When you cycle Nimble Obstructionist, counter target activated or triggered ability you don't control.

Narset, Parter of Veils

Each opponent can't draw more than one card each turn.
−2: Look at the top four cards of your library. You may reveal a noncreature, nonland card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Merfolk Trickster

Flash
When Merfolk Trickster enters, tap target creature an opponent controls. It loses all abilities until end of turn.

Shadow Kin

Flash
At the beginning of your upkeep, each player mills three cards. You may exile a creature card from among the cards milled this way. If you do, Shadow Kin becomes a copy of that card, except it has this ability.

Overcharged Amalgam

Flash
Flying
Exploit (When this creature enters, you may sacrifice a creature.)
When Overcharged Amalgam exploits a creature, counter target spell, activated ability, or triggered ability.

Voracious Greatshark

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, counter target artifact or creature spell.