Crocanura

Reach (This creature can block creatures with flying.)
Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Deranged Assistant

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Ghoulcaller's Bell

Lightning Greaves

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

Perpetual Timepiece

{T}: Mill two cards.
{2}, Exile this artifact: Shuffle any number of target cards from your graveyard into your library.

Thought Scour

Target player mills two cards.
Draw a card.

Biomass Mutation

Creatures you control have base power and toughness X/X until end of turn.

Laboratory Maniac

If you would draw a card while your library has no cards in it, you win the game instead.

Rapid Hybridization

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

Omnibian

{T}: Target creature becomes a Frog with base power and toughness 3/3 until end of turn.

Tome Scour

Forest

Willow Geist

Trample
Whenever one or more cards leave your graveyard, put a +1/+1 counter on this creature.
When this creature dies, you gain life equal to its power.

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

Cavern of Souls

As this land enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

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.)

Unclaimed Territory

As this land enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type.

Kasmina's Transmutation

Enchant creature
Enchanted creature loses all abilities and has base power and toughness 1/1.

Nature's Claim

Destroy target artifact or enchantment. Its controller gains 4 life.

Millikin

Breeding Pool

({T}: Add {G} or {U}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Frogify

Enchant creature
Enchanted creature loses all abilities and is a blue Frog creature with base power and toughness 1/1. (It loses all other card types and creature types.)

Codex Shredder

{T}: Target player mills a card. (They put the top card of their library into their graveyard.)
{5}, {T}, Sacrifice this artifact: Return target card from your graveyard to your hand.

Island

Whiptongue Frog

{U}: This creature gains flying until end of turn.

Anurid Scavenger

Protection from black
At the beginning of your upkeep, sacrifice this creature unless you put a card from your graveyard on the bottom of your library.

Chronic Flooding

Enchant land
Whenever enchanted land becomes tapped, its controller mills three cards.

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Mesmeric Orb

Whenever a permanent becomes untapped, that permanent's controller mills a card.

Bloated Toad

Protection from blue
Cycling {2} ({2}, Discard this card: Draw a card.)

Halo Hopper

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)

Simic Growth Chamber

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {G}{U}.

Polymorphist's Jest

Until end of turn, each creature target player controls loses all abilities and becomes a blue Frog with base power and toughness 1/1.

Poison Dart Frog

Reach
{T}: Add one mana of any color.
{2}: This creature gains deathtouch until end of turn.

Spore Frog

Sacrifice this creature: Prevent all combat damage that would be dealt this turn.

Otherworldly Gaze

Surveil 3. (Look at the top three cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Chub Toad

Whenever this creature blocks or becomes blocked, it gets +2/+2 until end of turn.

Leapfrog

This creature has flying as long as you've cast an instant or sorcery spell this turn.

Hedron Crab

Landfall — Whenever a land you control enters, target player mills three cards. (They put the top three cards of their library into their graveyard.)

Kodama's Reach

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Dream Twist

Target player mills three cards.
Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Arcane Signet

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

Anurid Swarmsnapper

Reach (This creature can block creatures with flying.)
{1}{G}: This creature can block an additional creature this turn.

Command Tower

Hinterland Harbor

This land enters tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Grolnok, the Omnivore

Whenever a Frog you control attacks, mill three cards.
Whenever a permanent card is put into your graveyard from your library, exile it with a croak counter on it.
You may play lands and cast spells from among cards you own in exile with croak counters on them.

Burrog Befuddler

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, target creature an opponent controls gets -1/-0 until end of turn.

Filter Out

Return all noncreature, nonland permanents to their owners' hands.

Jade Avenger

Bushido 2 (Whenever this creature blocks or becomes blocked, it gets +2/+2 until end of turn.)

Sol Ring

Croaking Counterpart

Create a token that's a copy of target non-Frog creature, except it's a 1/1 green Frog.
Flashback {3}{G}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Wilt

Destroy target artifact or enchantment.
Cycling {2} ({2}, Discard this card: Draw a card.)

Plaxcaster Frogling

Graft 3 (This creature enters with three +1/+1 counters on it. Whenever another creature enters, you may move a +1/+1 counter from this creature onto it.)
{2}: Target creature with a +1/+1 counter on it gains shroud until end of turn. (It can't be the target of spells or abilities.)

Galloping Lizrog

Trample
When this creature enters, you may remove any number of +1/+1 counters from among creatures you control. If you do, put twice that many +1/+1 counters on this creature.

Traumatize

Target player mills half their library, rounded down.

Mithril Coat

Flash
Indestructible
When Mithril Coat enters, attach it to target legendary creature you control.
Equipped creature has indestructible.
Equip {3}

Thassa's Oracle

When this creature enters, look at the top X cards of your library, where X is your devotion to blue. Put up to one of them on top of your library and the rest on the bottom of your library in a random order. If X is greater than or equal to the number of cards in your library, you win the game. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Froghemoth

Trample, haste
Whenever this creature deals combat damage to a player, exile up to that many target cards from their graveyard. Put a +1/+1 counter on this creature for each creature card exiled this way. You gain 1 life for each noncreature card exiled this way.

Vineglimmer Snarl

As this land enters, you may reveal a Forest or Island card from your hand. If you don't, this land enters tapped.
{T}: Add {G} or {U}.

Jace's Erasure

Whenever you draw a card, you may have target player mill a card.

Papercraft Decoy

When this creature leaves the battlefield, you may pay {2}. If you do, draw a card.

Fact or Fiction

Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Kenrith's Transformation

Enchant creature
When this Aura enters, draw a card.
Enchanted creature loses all abilities and is a green Elk creature with base power and toughness 3/3. (It loses all other card types and creature types.)

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Rejuvenating Springs

This land enters tapped unless you have two or more opponents.
{T}: Add {G} or {U}.

Mulch

Reveal the top four cards of your library. Put all land cards revealed this way into your hand and the rest into your graveyard.

Dreamroot Cascade

This land enters tapped unless you control two or more other lands.
{T}: Add {G} or {U}.

Tribute to the World Tree

Whenever a creature you control enters, draw a card if its power is 3 or greater. Otherwise, put two +1/+1 counters on it.

Excavating Anurid

When this creature enters, you may sacrifice a land. If you do, draw a card.
Threshold — As long as seven or more cards are in your graveyard, this creature gets +1/+1 and has vigilance.

Steeple Creeper

{3}{U}: This creature gains flying until end of turn.

Murkfiend Liege

Other green creatures you control get +1/+1.
Other blue creatures you control get +1/+1.
Untap all green and/or blue creatures you control during each other player's untap step.

Witness Protection

Enchant creature
Enchanted creature loses all abilities and is a green and white Citizen creature with base power and toughness 1/1 named Legitimate Businessperson. (It loses all other colors, card types, creature types, and names.)

Turn to Frog

Until end of turn, target creature loses all abilities and becomes a blue Frog with base power and toughness 1/1.

Trollbred Guardian

{2}{G}: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.)
Each creature you control with a +1/+1 counter on it has trample.

Explore

You may play an additional land this turn.
Draw a card.

Desecrated Tomb

Whenever one or more creature cards leave your graveyard, create a 1/1 black Bat creature token with flying.