Fellwar Stone

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

Mercurial Transformation

Until end of turn, target nonland permanent loses all abilities and becomes your choice of a blue Frog creature with base power and toughness 1/1 or a blue Octopus creature with base power and toughness 4/4.

Pollywog Symbiote

Each creature spell you cast costs {1} less to cast if it has mutate.
Whenever you cast a creature spell, if it has mutate, draw a card, then discard a card.

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.

Poison Dart Frog

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

River Heralds' Boon

Put a +1/+1 counter on target creature and a +1/+1 counter on up to one target Merfolk.

Sol Ring

Kasmina's Transmutation

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

Network Terminal

{T}: Add one mana of any color.
{1}, {T}, Tap another untapped artifact you control: Draw a card, then discard a card.

Jade Avenger

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

Leapfrog

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

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.

Springleaf Drum

{T}, Tap an untapped creature you control: Add one mana of any color.

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.)

Thran Dynamo

Forest

Papercraft Decoy

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

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.)

Flooded Grove

{T}: Add {C}.
{G/U}, {T}: Add {G}{G}, {G}{U}, or {U}{U}.

Moonsilver Key

{1}, {T}, Sacrifice Moonsilver Key: Search your library for an artifact card with a mana ability or a basic land card, reveal it, put it into your hand, then shuffle.

Ashnod's Altar

Thriving Grove

Thriving Grove enters tapped. As it enters, choose a color other than green.
{T}: Add {G} or one mana of the chosen color.

Turn to Frog

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

Ecological Appreciation

Search your library and graveyard for up to four creature cards with different names that each have mana value X or less and reveal them. An opponent chooses two of those cards. Shuffle the chosen cards into your library and put the rest onto the battlefield. Exile Ecological Appreciation.

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.)

Island

Chub Toad

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

Visions of Dominance

Put a +1/+1 counter on target creature, then double the number of +1/+1 counters on it.
Flashback {8}{G}{G}. This spell costs {X} less to cast this way, where X is the greatest mana value of a commander you own on the battlefield or in the command zone. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Might of Murasa

Kicker {2}{G} (You may pay an additional {2}{G} as you cast this spell.)
Target creature gets +3/+3 until end of turn. If this spell was kicked, that creature gets +5/+5 until end of turn instead.

Enchantment Alteration

Attach target Aura attached to a creature or land to another permanent of that type.

Incongruity

Exile target creature. That creature's controller creates a 3/3 green Frog Lizard creature token.

Incubation

Look at the top five cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Incubation // Incongruity

Anurid Swarmsnapper

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

Thought Vessel

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

Letter of Acceptance

{T}: Add one mana of any color.
{2}, {T}, Sacrifice Letter of Acceptance: Draw a card.

Gilded Lotus

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.)

Commander's Sphere

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

Misty Rainforest

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

Froghemoth

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

Lightning Greaves

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

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice this artifact: Draw two cards.

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

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}.

Frog Tongue

Enchant creature
When Frog Tongue enters, draw a card.
Enchanted creature has reach. (It can block creatures with flying.)

Biomass Mutation

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

Anurid Scavenger

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

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.

Frogmite

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)

Species Gorger

At the beginning of your upkeep, return a creature you control to its owner's hand.

Unstable Obelisk

{T}: Add {C}.
{7}, {T}, Sacrifice Unstable Obelisk: Destroy target permanent.

Expanded Anatomy

Put two +1/+1 counters on target creature. It gains vigilance until end of turn.

Anurid Barkripper

Threshold — Anurid Barkripper gets +2/+2 as long as seven or more cards are in your graveyard.

Galloping Lizrog

Trample
When Galloping Lizrog 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 Galloping Lizrog.

Arcane Signet

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

Whiptongue Hydra

Reach
When Whiptongue Hydra enters, destroy all creatures with flying. Put a +1/+1 counter on Whiptongue Hydra for each creature destroyed this way.

Rapid Hybridization

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

Sky Diamond

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Explore

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

Tomorrow, Azami's Familiar

If you would draw a card, look at the top three cards of your library instead. Put one of those cards into your hand and the rest on the bottom of your library in any order.

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.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Fabled Passage

{T}, Sacrifice Fabled Passage: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

Bloated Toad

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

Excavating Anurid

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

Hopping Automaton

{0}: Hopping Automaton gets -1/-1 and gains flying until end of turn.

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.

Spore Frog

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

Ebony Fly

Ebony Fly enters tapped.
{T}: Add {C}.
{4}: Roll a d6. Until end of turn, you may have Ebony Fly become an X/X Insect artifact creature with flying, where X is the result.
Whenever Ebony Fly attacks, another target attacking creature gains flying until end of turn.