Wan Shi Tong, Librarian

Flash
Flying, vigilance
When Wan Shi Tong enters, put X +1/+1 counters on him. Then draw half X cards, rounded down.
Whenever an opponent searches their library, put a +1/+1 counter on Wan Shi Tong and draw a card.

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Rejuvenating Springs

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

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Beast Within

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

Asceticism

Creatures you control have hexproof.
{1}{G}: Regenerate target creature. (The next time it would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

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.

Lilysplash Mentor

Reach
{1}{G}{U}: Exile another target creature you control, then return it to the battlefield under its owner's control with a +1/+1 counter on it. Activate only as a sorcery.

Island

Secret Tunnel

This land can't be blocked.
{T}: Add {C}.
{4}, {T}: Two target creatures you control that share a creature type can't be blocked this turn.

Ghalta, Primal Hunger

This spell costs {X} less to cast, where X is the total power of creatures you control.
Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Sol Ring

Verdant Catacombs

{T}, Pay 1 life, Sacrifice this land: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Dreamdew Entrancer

Reach
When this creature enters, tap up to one target creature and put three stun counters on it. If you control that creature, draw two cards.

Poison Dart Frog

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

Valley Floodcaller

Flash
You may cast noncreature spells as though they had flash.
Whenever you cast a noncreature spell, Birds, Frogs, Otters, and Rats you control get +1/+1 until end of turn. Untap them.

Azusa, Lost but Seeking

You may play two additional lands on each of your turns.

Command Tower

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

Long River's Pull

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
Counter target creature spell. If the gift was promised, instead counter target spell.

Flusterstorm

Counter target instant or sorcery spell unless its controller pays {1}.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Valley Mightcaller

Trample
Whenever another Frog, Rabbit, Raccoon, or Squirrel you control enters, put a +1/+1 counter on this creature.

Entomb

Search your library for a card, put that card into your graveyard, then shuffle.

Contaminated Aquifer

({T}: Add {U} or {B}.)
This land enters tapped.

Negate

Crash of Rhino Beetles

Trample
This creature gets +10/+10 as long as you control ten or more lands.

Wonder

Flying
As long as this card is in your graveyard and you control an Island, creatures you control have flying.

Frantic Search

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

Bender's Waterskin

Untap this artifact during each other player's untap step.
{T}: Add one mana of any color.

Inundated Archive

This land enters tapped.
{T}: Add {U} or {B}.

Waterlogged Teachings

Search your library for an instant card or a card with flash, reveal it, put it into your hand, then shuffle.

Waterlogged Teachings // Inundated Archive

Deep Analysis

Target player draws two cards.
Flashback—{1}{U}, Pay 3 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Polluted Delta

{T}, Pay 1 life, Sacrifice this land: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Fell Mire

As this land enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {B}.

Fell the Profane

Fell the Profane // Fell Mire

Undergrowth Stadium

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

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.)

Rampaging Brontodon

Trample
Whenever this creature attacks, it gets +1/+1 until end of turn for each land you control.

Scute Swarm

Landfall — Whenever a land you control enters, create a 1/1 green Insect creature token. If you control six or more lands, create a token that's a copy of this creature instead.

Worldly Tutor

Search your library for a creature card, reveal it, then shuffle and put the card on top.

Psychic Frog

Whenever this creature deals combat damage to a player or planeswalker, draw a card.
Discard a card: Put a +1/+1 counter on this creature.
Exile three cards from your graveyard: This creature gains flying until end of turn.

Simic Signet

Doomsday

Search your library and graveyard for five cards and exile the rest. Put the chosen cards on top of your library in any order. You lose half your life, rounded up.

Druid Class

(Gain the next level as a sorcery to add its ability.)
Landfall — Whenever a land you control enters, you gain 1 life.
{2}{G}: Level 2
You may play an additional land on each of your turns.
{4}{G}: Level 3
When this Class becomes level 3, target land you control becomes a creature with haste and "This creature's power and toughness are each equal to the number of lands you control." It's still a land.

Heaped Harvest

When this artifact enters and when you sacrifice it, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
{2}, {T}, Sacrifice this artifact: You gain 3 life.

Imprisoned in the Moon

Enchant creature, land, or planeswalker
Enchanted permanent is a colorless land with "{T}: Add {C}" and loses all other card types and abilities.

Birds of Paradise

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.)

Long River Lurker

Ward {1}
Other Frogs you control have ward {1}.
When this creature enters, target creature you control can't be blocked this turn. Whenever that creature deals combat damage this turn, you may exile it. If you do, return it to the battlefield under its owner's control.

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Opulent Palace

This land enters tapped.
{T}: Add {B}, {G}, or {U}.

Tatyova, Benthic Druid

Landfall — Whenever a land you control enters, you gain 1 life and draw a card.

Arcane Signet

Heartless Act

Choose one —
• Destroy target creature with no counters on it.
• Remove up to three counters from target creature.

Sodden Verdure

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

Thought Vessel

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

Soporific Springs

As this land enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {U}.

Sink into Stupor

Return target spell or nonland permanent an opponent controls to its owner's hand.

Sink into Stupor // Soporific Springs

Serpent's Pass

This land enters tapped.
{T}: Add {U} or {B}.
{4}, {T}, Sacrifice this land: Draw a card.

Rune-Scarred Demon

Flying
When this creature enters, search your library for a card, put it into your hand, then shuffle.

Snakeskin Veil

Put a +1/+1 counter on target creature you control. It gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Personal Tutor

Search your library for a sorcery card, reveal it, then shuffle and put that card on top.

Run Away Together

Choose two target creatures controlled by different players. Return those creatures to their owners' hands.

Mistbreath Elder

At the beginning of your upkeep, return another creature you control to its owner's hand. If you do, put a +1/+1 counter on this creature. Otherwise, you may return this creature to its owner's hand.

Counterspell

Golgari Signet

Death Begets Life

Destroy all creatures and enchantments. Draw a card for each permanent destroyed this way.

The Unagi of Kyoshi Island

Flash
Ward—Waterbend {4}. (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {4}. They can tap their artifacts and creatures to help. Each one pays for {1}.)
Whenever an opponent draws their second card each turn, you draw two cards.

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.

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Glarb, Calamity's Augur

Deathtouch
You may look at the top card of your library any time.
You may play lands and cast spells with mana value 4 or greater from the top of your library.
{T}: Surveil 2.

Foreboding Landscape

{T}: Add {C}.
{T}, Sacrifice this land: Search your library for a basic Swamp, Forest, or Island card, put it onto the battlefield tapped, then shuffle.
Cycling {B}{G}{U} ({B}{G}{U}, Discard this card: Draw a card.)

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.")

Clement, the Worrywort

Vigilance
Whenever Clement or another creature you control enters, return up to one target creature you control with lesser mana value to its owner's hand.
Frogs you control have "{T}: Add {G} or {U}. Spend this mana only to cast a creature spell."

Reliquary Tower

Meditation Pools

This land enters tapped.
{T}: Add {G} or {U}.
{4}, {T}, Sacrifice this land: Draw a card.

Laboratory Maniac

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

Amphibian Downpour

Flash
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies. Copies become tokens.)
Enchant creature
Enchanted creature loses all abilities and is a blue Frog creature with base power and toughness 1/1.

Forest

Misty Rainforest

{T}, Pay 1 life, Sacrifice this land: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

Colossal Grave-Reaver

Flying
Whenever this creature enters or attacks, mill three cards.
Whenever one or more creature cards are put into your graveyard from your library, put one of them onto the battlefield.

Boggart Bog

Boggart Trawler

When this creature enters, exile target player's graveyard.

Boggart Trawler // Boggart Bog

Dour Port-Mage

Whenever one or more other creatures you control leave the battlefield without dying, draw a card.
{1}{U}, {T}: Return another target creature you control to its owner's hand.

Old-Growth Grove

This land enters tapped.
{T}: Add {B} or {G}.

Revitalizing Repast

Put a +1/+1 counter on target creature. It gains indestructible until end of turn.

Revitalizing Repast // Old-Growth Grove

Volatile Fault

{T}: Add {C}.
{1}, {T}, Sacrifice this land: Destroy target nonbasic land an opponent controls. That player may search their library for a basic land card, put it onto the battlefield, then shuffle. You create a Treasure token.

Bloom Tender

Vivid — {T}: For each color among permanents you control, add one mana of that color.

Brainstorm

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

Haunted Mire

({T}: Add {B} or {G}.)
This land enters tapped.

Swamp

Cycle of Renewal

Sacrifice a land. Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Loyal Guardian

Trample
Lieutenant — At the beginning of combat on your turn, if you control your commander, put a +1/+1 counter on each creature you control.