Leyline of Transformation

If Leyline of Transformation is in your opening hand, you may begin the game with it on the battlefield.
As Leyline of Transformation enters, choose a creature type.
Creatures you control are the chosen type in addition to their other types. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.

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.")

Release the Dogs

Create four 1/1 white Dog creature tokens.

Metallic Mimic

As Metallic Mimic enters, choose a creature type.
Metallic Mimic is the chosen type in addition to its other types.
Each other creature you control of the chosen type enters with an additional +1/+1 counter on it.

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.

Plains

Temple of Mystery

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {G} or {U}.

Temple of Plenty

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {G} or {W}.

Mushroom Watchdogs

Sacrifice a Food: Put a +1/+1 counter on Mushroom Watchdogs. It gains vigilance until end of turn. Activate only as a sorcery.

Bloodline Pretender

Changeling (This card is every creature type.)
As Bloodline Pretender enters, choose a creature type.
Whenever another creature you control of the chosen type enters, put a +1/+1 counter on Bloodline Pretender.

Krovod Haunch

Equipped creature gets +2/+0.
{2}, {T}, Sacrifice Krovod Haunch: You gain 3 life.
When Krovod Haunch is put into a graveyard from the battlefield, you may pay {1}{W}. If you do, create two 1/1 white Dog creature tokens.
Equip {2}

Wary Watchdog

When Wary Watchdog enters or dies, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Thorough Investigation

Whenever you attack, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Whenever you sacrifice a Clue, venture into the dungeon. (Enter the first room or advance to the next room.)

Ozolith, the Shattered Spire

If one or more +1/+1 counters would be put on an artifact or creature you control, that many plus one +1/+1 counters are put on it instead.
{1}{G}, {T}: Put a +1/+1 counter on target artifact or creature you control. Activate only as a sorcery.
Cycling {2} ({2}, Discard this card: Draw a card.)

Talisman of Curiosity

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

Patchwork Banner

As Patchwork Banner enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{T}: Add one mana of any color.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Gilded Goose

Flying
When Gilded Goose enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
{1}{G}, {T}: Create a Food token.
{T}, Sacrifice a Food: Add one mana of any color.

Abzan Falconer

Outlast {W} ({W}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has flying.

Mossdog

Whenever Mossdog becomes the target of a spell or ability an opponent controls, put a +1/+1 counter on Mossdog.

Tranquil Landscape

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

Yavimaya Coast

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

Faithful Watchdog

Vigilance
Faithful Watchdog enters with three +1/+1 counters on it.

Ainok Bond-Kin

Outlast {1}{W} ({1}{W}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has first strike.

Phelia, Exuberant Shepherd

Flash
Whenever Phelia, Exuberant Shepherd attacks, exile up to one other target nonland permanent. At the beginning of the next end step, return that card to the battlefield under its owner's control. If it entered under your control, put a +1/+1 counter on Phelia.

Boros Mastiff

Battalion — Whenever Boros Mastiff and at least two other creatures attack, Boros Mastiff gains lifelink until end of turn. (Damage dealt by a creature with lifelink also causes its controller to gain that much life.)

Supreme Verdict

This spell can't be countered.
Destroy all creatures.

Hardened Scales

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on it instead.

Arcane Signet

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

Canopy Vista

({T}: Add {G} or {W}.)
Canopy Vista enters tapped unless you control two or more basic lands.

The Shire

The Shire enters tapped unless you control a legendary creature.
{T}: Add {G}.
{1}{G}, {T}, Tap an untapped creature you control: Create a Food token.

Talisman of Progress

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

Inspiring Statuary

Nonartifact spells you cast have improvise. (Your artifacts can help cast those spells. Each artifact you tap after you're done activating mana abilities pays for {1}.)

Adarkar Wastes

{T}: Add {C}.
{T}: Add {W} or {U}. Adarkar Wastes deals 1 damage to you.

Unsettled Mariner

Changeling (This card is every creature type.)
Whenever you or a permanent you control becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {1}.

Sea of Clouds

Sea of Clouds enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Warclamp Mastiff

First strike (This creature deals combat damage before creatures without first strike.)

Spirited Companion

When Spirited Companion enters, draw a card.

Apothecary White

Vigilance
Whenever you attack, you create a Food token for each player being attacked. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
{W}, {T}, Tap X untapped Foods you control: Create X 1/1 white Human creature tokens.

Temple of Enlightenment

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {W} or {U}.

Iron Mastiff

Whenever Iron Mastiff attacks, roll a d20 for each player being attacked and ignore all but the highest roll.
1—9 | Iron Mastiff deals damage equal to its power to you.
10—19 | Iron Mastiff deals damage equal to its power to defending player.
20 | Iron Mastiff deals damage equal to its power to each opponent.

Pack Leader

Other Dogs you control get +1/+1.
Whenever Pack Leader attacks, prevent all combat damage that would be dealt this turn to Dogs you control.

Forest

Yotian Dissident

Whenever an artifact you control enters, put a +1/+1 counter on target creature you control.

Dreamroot Cascade

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

Karlov Watchdog

Vigilance
Permanents your opponents control can't be turned face up during your turn.
Whenever you attack with three or more creatures, creatures you control get +1/+1 until end of turn.

Archway of Innovation

Archway of Innovation enters tapped unless you control an Island.
{T}: Add {U}.
{U}, {T}: The next spell you cast this turn has improvise. (Your artifacts can help cast that spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)

Generous Gift

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

Tireless Tracker

Landfall — Whenever a land you control enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Whenever you sacrifice a Clue, put a +1/+1 counter on Tireless Tracker.

Realmwalker

Changeling (This card is every creature type.)
As Realmwalker enters, choose a creature type.
You may look at the top card of your library any time.
You may cast creature spells of the chosen type from the top of your library.

Herald of Secret Streams

Creatures you control with +1/+1 counters on them can't be blocked.

Branching Evolution

If one or more +1/+1 counters would be put on a creature you control, twice that many +1/+1 counters are put on that creature instead.

Return of the Wildspeaker

Choose one —
• Draw cards equal to the greatest power among non-Human creatures you control.
• Non-Human creatures you control get +3/+3 until end of turn.

Seaside Citadel

Seaside Citadel enters tapped.
{T}: Add {G}, {W}, or {U}.

Bayou Groff

As an additional cost to cast this spell, sacrifice a creature or pay {3}.

Prairie Stream

({T}: Add {W} or {U}.)
Prairie Stream enters tapped unless you control two or more basic lands.

Isamaru, Hound of Konda

Glacial Fortress

Glacial Fortress enters tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Farewell

Choose one or more —
• Exile all artifacts.
• Exile all creatures.
• Exile all enchantments.
• Exile all graveyards.

Sunpetal Grove

Sunpetal Grove enters tapped unless you control a Forest or a Plains.
{T}: Add {G} or {W}.

Brokers Ascendancy

At the beginning of your end step, put a +1/+1 counter on each creature you control and a loyalty counter on each planeswalker you control.

Killer Service

When Killer Service enters, create a number of Food tokens equal to the number of opponents you have. (They're artifacts with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
At the beginning of your end step, you may pay {2} and sacrifice a token. If you do, create a 4/4 green Rhino Warrior creature token.

Rosie Cotton of South Lane

When Rosie Cotton of South Lane enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
Whenever you create a token, put a +1/+1 counter on target creature you control other than Rosie.

Gavony Township

{T}: Add {C}.
{2}{G}{W}, {T}: Put a +1/+1 counter on each creature you control.

Animal Sanctuary

{T}: Add {C}.
{2}, {T}: Put a +1/+1 counter on target Bird, Cat, Dog, Goat, Ox, or Snake.

Tangletrove Kelp

Ward {2}
At the beginning of each combat, other Clues you control become 6/6 Plant creatures in addition to their other types until end of turn.
{2}, Sacrifice Tangletrove Kelp: Draw a card.

Kitchen

Kitchen enters tapped.
{T}: Add {G} or {U}.
{4}, {T}: Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Mechanized Production

Enchant artifact you control
At the beginning of your upkeep, create a token that's a copy of enchanted artifact. Then if you control eight or more artifacts with the same name as one another, you win the game.

Island

Brushland

{T}: Add {C}.
{T}: Add {G} or {W}. Brushland deals 1 damage to you.

Mischievous Pup

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, return up to one other target permanent you control to its owner's hand.

Mowu, Loyal Companion

Vigilance, trample
If one or more +1/+1 counters would be put on Mowu, Loyal Companion, that many plus one +1/+1 counters are put on it instead.

Dispatch

Tap target creature.
Metalcraft — If you control three or more artifacts, exile that creature.

Command Tower

Reliquary Tower

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

Adrix and Nev, Twincasters

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
If one or more tokens would be created under your control, twice that many of those tokens are created instead.

Sol Ring

Study

Study enters tapped.
{T}: Add {W} or {U}.
{4}, {T}: Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Academy Manufactor

If you would create a Clue, Food, or Treasure token, instead create one of each.

Yoshimaru, Ever Faithful

Whenever another legendary permanent you control enters, put a +1/+1 counter on Yoshimaru, Ever Faithful.
Partner (You can have two commanders if both have partner.)

Talisman of Unity

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

Sterling Hound

When Sterling Hound enters, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Bountiful Promenade

Bountiful Promenade enters tapped unless you have two or more opponents.
{T}: Add {G} or {W}.

Thoughtcast

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

Fountainport

{T}: Add {C}.
{2}, {T}, Sacrifice a token: Draw a card.
{3}, {T}, Pay 1 life: Create a 1/1 blue Fish creature token.
{4}, {T}: Create a Treasure token.

Deserted Beach

Deserted Beach enters tapped unless you control two or more other lands.
{T}: Add {W} or {U}.

Sophia, Dogged Detective

When Sophia, Dogged Detective enters, create Tiny, a legendary 2/2 green Dog Detective creature token with trample.
{1}, Sacrifice an artifact token: Put a +1/+1 counter on each Dog you control.
Whenever a Dog you control deals combat damage to a player, create a Food token, then investigate.

Mongrel Pack

When Mongrel Pack dies during combat, create four 1/1 green Dog creature tokens.

Bred for the Hunt

Whenever a creature you control with a +1/+1 counter on it deals combat damage to a player, you may draw a card.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Overgrown Farmland

Overgrown Farmland enters tapped unless you control two or more other lands.
{T}: Add {G} or {W}.

Drannith Ruins

{T}: Add {C}.
{2}, {T}: Put two +1/+1 counters on target non-Human creature that entered this turn.

Spara's Headquarters

({T}: Add {G}, {W}, or {U}.)
Spara's Headquarters enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Hinterland Harbor

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

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Peregrin Took

If one or more tokens would be created under your control, those tokens plus an additional Food token are created instead. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
Sacrifice three Foods: Draw a card.

Elven Warhounds

Whenever Elven Warhounds becomes blocked by a creature, put that creature on top of its owner's library.

Rejuvenating Springs

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