Sol Ring

Quickling

Flash (You may cast this spell any time you could cast an instant.)
Flying
When Quickling enters, sacrifice it unless you return another creature you control to its owner's hand.

Temple of Mystery

Temple of Mystery enters tapped.
When Temple of Mystery enters, scry 1.
{T}: Add {G} or {U}.

Meneldor, Swift Savior

Flying
Whenever Meneldor, Swift Savior deals combat damage to a player, exile up to one target creature you own, then return it to the battlefield under your control.

Arcane Signet

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

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.

Frilled Mystic

Flash
When Frilled Mystic enters, you may counter target spell.

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.

Wave Goodbye

Return each creature without a +1/+1 counter on it to its owner's hand.

Intruder Alarm

Creatures don't untap during their controllers' untap steps.
Whenever a creature enters, untap all creatures.

Bellowing Crier

When Bellowing Crier enters, draw a card, then discard a card.

Great Oak Guardian

Flash (You may cast this spell any time you could cast an instant.)
Reach
When Great Oak Guardian enters, creatures target player controls get +2/+2 until end of turn. Untap them.

Mirror of Life Trapping

Whenever a creature enters, if it was cast, exile it, then return all other permanent cards exiled with Mirror of Life Trapping to the battlefield under their owners' control.

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.

Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

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.

Portal Mage

Flash
When Portal Mage enters during the declare attackers step, you may reselect which player or permanent target attacking creature is attacking. (It can't attack its controller or their permanents.)

Overprotect

Target creature you control gets +3/+3 and gains trample, hexproof, and indestructible until end of turn.

Pond Prophet

Three Tree Scribe

Whenever Three Tree Scribe or another creature you control leaves the battlefield without dying, put a +1/+1 counter on target creature you control.

Ancient Imperiosaur

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.)
Trample, ward {2}
Ancient Imperiosaur enters with two +1/+1 counters on it for each creature that convoked it.

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.

Coiling Oracle

When Coiling Oracle enters, reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put that card into your hand.

Mirror Image

You may have Mirror Image enter as a copy of a creature you control.

Mist Raven

Flying
When Mist Raven enters, return target creature to its owner's hand.

Smuggler's Surprise

Spree (Choose one or more additional costs.)
+ {2} — Mill four cards. You may put up to two creature and/or land cards from among the milled cards into your hand.
+ {4}{G} — You may put up to two creature cards from your hand onto the battlefield.
+ {1} — Creatures you control with power 4 or greater gain hexproof and indestructible until end of turn.

Oakhollow Village

{T}: Add {C}.
{T}: Add {G}. Spend this mana only to cast a creature spell.
{G}, {T}: Put a +1/+1 counter on each Frog, Rabbit, Raccoon, or Squirrel you control that entered the battlefield this turn.

Path of Discovery

Whenever a creature you control enters, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on the creature, then put the card back or put it into your graveyard.)

Mockingbird

Flying
You may have Mockingbird enter as a copy of any creature on the battlefield with mana value less than or equal to the amount of mana spent to cast Mockingbird, except it's a Bird in addition to its other types and it has flying.

Botanical Sanctum

Botanical Sanctum enters tapped unless you control two or fewer other lands.
{T}: Add {G} or {U}.

Hinterland Harbor

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

Forest

Species Gorger

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

Forgotten Ancient

Whenever a player casts a spell, you may put a +1/+1 counter on Forgotten Ancient.
At the beginning of your upkeep, you may move any number of +1/+1 counters from Forgotten Ancient onto other creatures.

Bramble Sovereign

Whenever another nontoken creature enters, you may pay {1}{G}. If you do, that creature's controller creates a token that's a copy of that creature.

Champion of Lambholt

Creatures with power less than Champion of Lambholt's power can't block creatures you control.
Whenever another creature you control enters, put a +1/+1 counter on Champion of Lambholt.

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.

Harrier Strix

Flying
When Harrier Strix enters, tap target permanent.
{2}{U}: Draw a card, then discard a card.

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."

Peerless Ropemaster

When Peerless Ropemaster enters, return up to one target tapped creature to its owner's hand.

Thunderfoot Baloth

Trample
Lieutenant — As long as you control your commander, Thunderfoot Baloth gets +2/+2 and other creatures you control get +2/+2 and have trample.

Master Biomancer

Each other creature you control enters with a number of additional +1/+1 counters on it equal to Master Biomancer's power and as a Mutant in addition to its other types.

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.

Draining Whelk

Flash
Flying
When Draining Whelk enters, counter target spell. Put X +1/+1 counters on Draining Whelk, where X is that spell's mana value.

Reflections of Littjara

As Reflections of Littjara enters, choose a creature type.
Whenever you cast a spell of the chosen type, copy that spell. (A copy of a permanent spell becomes a token.)

Sunshower Druid

When Sunshower Druid enters, put a +1/+1 counter on target creature and you gain 1 life.

Splash Lasher

Offspring {1}{U} (You may pay an additional {1}{U} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
When this creature enters, tap up to one target creature and put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

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.

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.

Spore Frog

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

Flooded Grove

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

Command Tower

Valley Mightcaller

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

High Stride

Target creature gets +1/+3 and gains reach until end of turn. Untap it.

Moonsnare Specialist

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.)
When Moonsnare Specialist enters, return up to one target creature to its owner's hand.

Cultivate

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.

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.

Peregrine Drake

Flying
When Peregrine Drake enters, untap up to five lands.

Moritte of the Frost

Changeling (This card is every creature type.)
You may have Moritte of the Frost enter as a copy of a permanent you control, except it's legendary and snow in addition to its other types and, if it's a creature, it enters with two additional +1/+1 counters on it and has changeling.

Overflowing Basin

Unnatural Growth

At the beginning of each combat, double the power and toughness of each creature you control until end of turn.

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.

Island

Mystic Snake

Flash
When Mystic Snake enters, counter target spell.

Stickytongue Sentinel

Reach
When Stickytongue Sentinel enters, return up to one other target permanent you control to its owner's hand.

Full Steam Ahead

Until end of turn, each creature you control gets +2/+2 and gains trample and "This creature can't be blocked by more than one creature."

Polliwallop

This spell costs {1} less to cast for each Frog you control.
Target creature you control deals damage equal to twice its power to target creature you don't control.

This Town Ain't Big Enough

This spell costs {3} less to cast if it targets a permanent you control.
Return up to two target nonland permanents to their owners' hands.

Barrin, Tolarian Archmage

When Barrin, Tolarian Archmage enters, return up to one other target creature or planeswalker to its owner's hand.
At the beginning of your end step, if a permanent was put into your hand from the battlefield this turn, 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.

Wood Elves

When Wood Elves enters, search your library for a Forest card, put that card onto the battlefield, then shuffle.

Innkeeper's Talent

(Gain the next level as a sorcery to add its ability.)
At the beginning of combat on your turn, put a +1/+1 counter on target creature you control.
{G}: Level 2
Permanents you control with counters on them have ward {1}.
{3}{G}: Level 3
If you would put one or more counters on a permanent or player, put twice that many of each of those kinds of counters on that permanent or player instead.

Splash Portal

Exile target creature you control, then return it to the battlefield under its owner's control. If that creature is a Bird, Frog, Otter, or Rat, draw a card.

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 Mistbreath Elder. Otherwise, you may return Mistbreath Elder to its owner's hand.

Sylvan Ranger

When Sylvan Ranger enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.