Pollywog Prodigy

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.)
Whenever an opponent casts a noncreature spell with mana value less than Pollywog Prodigy's power, draw a card.

Rampant Frogantua

Trample
Rampant Frogantua gets +10/+10 for each player who has lost the game.
Whenever Rampant Frogantua deals combat damage to a player, you may mill that many cards. Put any number of land cards from among them onto the battlefield tapped.

Poison Dart Frog

Reach
{T}: Add one mana of any color.
{2}: Poison Dart Frog gains deathtouch until end of turn.

Sanctum Weaver

{T}: Add X mana of any one color, where X is the number of enchantments you control.

Underground River

{T}: Add {C}.
{T}: Add {U} or {B}. Underground River deals 1 damage to you.

The Gitrog Monster

Deathtouch
At the beginning of your upkeep, sacrifice The Gitrog Monster unless you sacrifice a land.
You may play an additional land on each of your turns.
Whenever one or more land cards are put into your graveyard from anywhere, draw a card.

Llanowar Wastes

{T}: Add {C}.
{T}: Add {B} or {G}. Llanowar Wastes deals 1 damage to you.

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.

Talisman of Curiosity

{T}: Add {C}.
{T}: Add {G} or {U}. Talisman of Curiosity deals 1 damage to you.

Opulent Palace

Opulent Palace enters tapped.
{T}: Add {B}, {G}, or {U}.

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.

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.)

Biomancer's Familiar

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.
{T}: The next time target creature adapts this turn, it adapts as though it had no +1/+1 counters on it.

Undercity Sewers

({T}: Add {U} or {B}.)
Undercity Sewers enters tapped.
When Undercity Sewers enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Heartstone

Activated abilities of creatures cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Spore Frog

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

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Yargle and Multani

Foreboding Landscape

{T}: Add {C}.
{T}, Sacrifice Foreboding Landscape: 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.)

Negate

The Gitrog, Ravenous Ride

Trample, haste
Whenever The Gitrog, Ravenous Ride deals combat damage to a player, you may sacrifice a creature that saddled it this turn. If you do, draw X cards, then put up to X land cards from your hand onto the battlefield tapped, where X is the sacrificed creature's power.
Saddle 1

Twenty-Toed Toad

Your maximum hand size is twenty.
Whenever you attack with two or more creatures, put a +1/+1 counter on Twenty-Toed Toad and draw a card.
Whenever Twenty-Toed Toad attacks, you win the game if there are twenty or more counters on it or you have twenty or more cards in hand.

Training Grounds

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Turn to Frog

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

Dimir Aqueduct

Dimir Aqueduct enters tapped.
When Dimir Aqueduct enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.

Yavimaya, Cradle of Growth

Each land is a Forest in addition to its other land types.

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Vanquisher's Banner

As Vanquisher's Banner enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
Whenever you cast a creature spell of the chosen type, draw a card.

Underground Mortuary

({T}: Add {B} or {G}.)
Underground Mortuary enters tapped.
When Underground Mortuary enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Cultivate

Exotic Orchard

Beast Within

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

Rapid Hybridization

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

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.

Tatsunari, Toad Rider

Whenever you cast an enchantment spell, if you don't control a creature named Keimi, create Keimi, a legendary 3/3 black and green Frog creature token with "Whenever you cast an enchantment spell, each opponent loses 1 life and you gain 1 life."
{1}{G/U}: Tatsunari, Toad Rider and target Frog you control can't be blocked this turn except by creatures with flying or reach.

Woodland Cemetery

Woodland Cemetery enters tapped unless you control a Swamp or a Forest.
{T}: Add {B} or {G}.

Sol Ring

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Psychic Frog

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

Counterspell

Dreamdew Entrancer

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

Reliquary Tower

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

Clement, the Worrywort

Vigilance
Whenever Clement, the Worrywort 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."

Omnibian

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

Dryad of the Ilysian Grove

You may play an additional land on each of your turns.
Lands you control are every basic land type in addition to their other types.

Deathcap Glade

Deathcap Glade enters tapped unless you control two or more other lands.
{T}: Add {B} or {G}.

Command Tower

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

Clifftop Lookout

Reach
When Clifftop Lookout enters, reveal cards from the top of your library until you reveal a land card. Put that card onto the battlefield tapped and the rest on the bottom of your library in a random order.

Assassin's Trophy

Destroy target permanent an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Drowned Catacomb

Drowned Catacomb enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Island

Spring Splasher

Whenever Spring Splasher attacks, target creature defending player controls gets -3/-0 until end of turn.

Golgari Rot Farm

Golgari Rot Farm enters tapped.
When Golgari Rot Farm enters, return a land you control to its owner's hand.
{T}: Add {B}{G}.

Jade Avenger

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

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Hedge Maze

({T}: Add {G} or {U}.)
Hedge Maze enters tapped.
When Hedge Maze enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

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.

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Shipwreck Marsh

Shipwreck Marsh enters tapped unless you control two or more other lands.
{T}: Add {U} or {B}.

Long River Lurker

Ward {1}
Other Frogs you control have ward {1}.
When Long River Lurker 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.

Octomancer

Gift an Octopus (You may promise an opponent a gift as you cast this spell. If you do, when it enters, they create an 8/8 blue Octopus creature token.)
At the beginning of each end step, create a token that's a copy of target creature token that entered the battlefield this turn.

Hinterland Harbor

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

Arcane Signet

Yavimaya Coast

{T}: Add {C}.
{T}: Add {G} or {U}. Yavimaya Coast deals 1 damage to you.

Swamp

Tempt with Discovery

Tempting offer — Search your library for a land card and put it onto the battlefield. Each opponent may search their library for a land card and put it onto the battlefield. For each opponent who searches a library this way, search your library for a land card and put it onto the battlefield. Then each player who searched a library this way shuffles.

Lilypad Village

{T}: Add {C}.
{T}: Add {U}. Spend this mana only to cast a creature spell.
{U}, {T}: Surveil 2. Activate only if a Bird, Frog, Otter, or Rat entered the battlefield under your control this turn.

Yargle, Glutton of Urborg

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Talisman of Resilience

{T}: Add {C}.
{T}: Add {B} or {G}. Talisman of Resilience deals 1 damage to you.

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.

Simic Growth Chamber

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

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. Talisman of Dominance deals 1 damage to you.

Kindred Discovery

As Kindred Discovery enters, choose a creature type.
Whenever a creature you control of the chosen type enters or attacks, draw a card.

Dreamroot Cascade

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