Thrummingbird

Flying
Whenever this creature deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Library Larcenist

Whenever this creature attacks, draw a card.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Gateway Sneak

Whenever a Gate you control enters, this creature can't be blocked this turn.
Whenever this creature deals combat damage to a player, draw a card.

Aetherize

Return all attacking creatures to their owner's hand.

Military Intelligence

Whenever you attack with two or more creatures, draw a card.

Crashing Drawbridge

Defender
{T}: Creatures you control gain haste until end of turn.

Neurok Commando

Shroud (This creature can't be the target of spells or abilities.)
Whenever this creature deals combat damage to a player, you may draw a card.

Brainstorm

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

Vexing Radgull

Flying
Whenever this creature deals combat damage to a player, that player gets two rad counters if they don't have any rad counters. Otherwise, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Coastal Piracy

Whenever a creature you control deals combat damage to an opponent, you may draw a card.

Serum Snare

Return target nonland permanent to its owner's hand. If that permanent had mana value 3 or less, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Prologue to Phyresis

Each opponent gets a poison counter.
Draw a card.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Triskaidekaphile

You have no maximum hand size.
At the beginning of your upkeep, if you have exactly thirteen cards in your hand, you win the game.
{3}{U}: Draw a card.

Siren Stormtamer

Flying
{U}, Sacrifice this creature: Counter target spell or ability that targets you or a creature you control.

Island

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Grazilaxx, Illithid Scholar

Whenever a creature you control becomes blocked, you may return it to its owner's hand.
Whenever one or more creatures you control deal combat damage to a player, draw a card.

Feywild Visitor

Commander creatures you own have "Whenever one or more nontoken creatures you control deal combat damage to a player, you create a 1/1 blue Faerie Dragon creature token with flying."

Reconnaissance Mission

Whenever a creature you control deals combat damage to a player, you may draw a card.
Cycling {2} ({2}, Discard this card: Draw a card.)

Ultimecia, Temporal Threat

When Ultimecia enters, tap all creatures your opponents control.
Whenever a creature you control deals combat damage to a player, draw a card.

Kaito, Cunning Infiltrator

Whenever a creature you control deals combat damage to a player, put a loyalty counter on Kaito.
+1: Up to one target creature you control can't be blocked this turn. Draw a card, then discard a card.
−2: Create a 2/1 blue Ninja creature token.
−9: You get an emblem with "Whenever a player casts a spell, you create a 2/1 blue Ninja creature token."

Inexorable Tide

Whenever you cast a spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Necropede

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When this creature dies, you may put a -1/-1 counter on target creature.

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Sol Ring

Mystic Sanctuary

({T}: Add {U}.)
This land enters tapped unless you control three or more other Islands.
When this land enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Counterspell

Malcolm, Alluring Scoundrel

Flash
Flying
Whenever Malcolm deals combat damage to a player, put a chorus counter on it. Draw a card, then discard a card. If there are four or more chorus counters on Malcolm, you may cast the discarded card without paying its mana cost.

Myr Convert

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
{T}, Pay 2 life: Add one mana of any color.

Scroll Thief

Whenever this creature deals combat damage to a player, draw a card.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Mistblade Shinobi

Ninjutsu {U} ({U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever this creature deals combat damage to a player, you may return target creature that player controls to its owner's hand.

Phyrexian Digester

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Nimble Brigand

This creature can't be blocked if you've committed a crime this turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)
Whenever this creature deals combat damage to a player, draw a card.

Kefnet's Monument

Blue creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, target creature an opponent controls doesn't untap during its controller's next untap step.

Tezzeret's Gambit

({U/P} can be paid with either {U} or 2 life.)
Draw two cards, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

The Indomitable

Trample
Whenever a creature you control deals combat damage to a player, draw a card.
Crew 3
You may cast this card from your graveyard as long as you control three or more tapped Pirates and/or Vehicles.

Guildpact Informant

Flying
Whenever this creature deals combat damage to a player or planeswalker, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Bloodforged Battle-Axe

Equipped creature gets +2/+0.
Whenever equipped creature deals combat damage to a player, create a token that's a copy of this Equipment.
Equip {2}

Corrupted Resolve

Counter target spell if its controller is poisoned.

Bident of Thassa

Whenever a creature you control deals combat damage to a player, you may draw a card.
{1}{U}, {T}: Creatures your opponents control attack this turn if able.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Reality Shift

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

Distorted Curiosity

Corrupted — This spell costs {2} less to cast if an opponent has three or more poison counters.
Draw two cards.

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Mist-Syndicate Naga

Ninjutsu {2}{U} ({2}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever this creature deals combat damage to a player, create a token that's a copy of this creature.

Prosthetic Injector

Equipped creature gets +0/+2 and has toxic 1. (Players dealt combat damage by equipped creature also get a poison counter.)
Equip {1}

Contentious Plan

Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Draw a card.

Blighted Agent

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
This creature can't be blocked.

Catlike Curiosity

Enchant creature
Enchanted creature has "Whenever this creature deals combat damage to a player, draw a card."
If Catlike Curiosity would be put into a graveyard from anywhere, exile it instead.

Mischievous Catgeist

Whenever this creature deals combat damage to a player, draw a card.
Disturb {2}{U} (You may cast this card from your graveyard transformed for its disturb cost.)

Mischievous Catgeist // Catlike Curiosity

Dune Mover

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When this creature enters, you may search your library for a basic land card, reveal it, then shuffle and put that card on top.

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Plague Myr

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{T}: Add {C}.

High Tide

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

Experimental Augury

Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Tandem Lookout

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Tandem Lookout is paired with another creature, each of those creatures has "Whenever this creature deals damage to an opponent, draw a card."

Viral Drake

Flying
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{3}{U}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Negate

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Quietus Spike

Equipped creature has deathtouch.
Whenever equipped creature deals combat damage to a player, that player loses half their life, rounded up.
Equip {3}

Mirrex

{T}: Add {C}.
{T}: Add one mana of any color. Activate only if this land entered this turn.
{3}, {T}: Create a 1/1 colorless Phyrexian Mite artifact creature token with toxic 1 and "This token can't block." (Players dealt combat damage by it also get a poison counter.)

Ponder

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

Curiosity

Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

Reliquary Tower

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Sapphire Medallion

Blue spells you cast cost {1} less to cast.

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Ichorclaw Myr

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever this creature becomes blocked, it gets +2/+2 until end of turn.

Tetsuko Umezawa, Fugitive

Creatures you control with power or toughness 1 or less can't be blocked.

Eternal of Harsh Truths

Afflict 2 (Whenever this creature becomes blocked, defending player loses 2 life.)
Whenever this creature attacks and isn't blocked, draw a card.