Hallowed Fountain

({T}: Add {W} or {U}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Bloodline Pretender

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

Realmwalker

Changeling (This card is every creature type.)
As this creature 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.

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.")

Martha Jones

Woman Who Walked the Earth — When Martha Jones enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Whenever you sacrifice a Clue, Martha Jones and up to one other target creature can't be blocked this turn.
Doctor's companion (You can have two commanders if the other is the Doctor.)

Clue

Elephant

Rejuvenating Springs

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

Flooded Strand

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

Kindred Discovery

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

Longshot Squad

Outlast {1}{G} ({1}{G}, {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 reach. (A creature with reach can block creatures with flying.)

Sea of Clouds

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

Beast Within

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

Tireless Tracker

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

Lightning Greaves

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

Sphere Grid

Whenever a creature you control deals combat damage to a player, put a +1/+1 counter on that creature.
Unlock Ability — Creatures you control with +1/+1 counters on them have reach and trample.

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.

Floodhound

{3}, {T}: Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

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.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Beast

K-9, Mark I

Negative — As long as K-9 is untapped, other legendary creatures you control have ward {1}.
Affirmative — {1}{U}, {T}: Target legendary creature can't be blocked this turn.
Doctor's companion (You can have two commanders if the other is the Doctor.)

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

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.

Alpine Watchdog

Vigilance (Attacking doesn't cause this creature to tap.)

Eldrazi

Mowu, Loyal Companion

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

Animal Sanctuary

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

Island

Stroke of Midnight

Destroy target nonland permanent. Its controller creates a 1/1 white Human creature token.

Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

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.

Food

{2}, {T}, Sacrifice this token: You gain 3 life.

Three Visits

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

Command Tower

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

Rosie Cotton of South Lane

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

Resolute Watchdog

Defender
{1}, Sacrifice this creature: Target creature you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

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.)

Forest

Generous Pup

Vigilance
Whenever one or more +1/+1 counters are put on this creature, put a +1/+1 counter on each other creature you control. This ability triggers only once each turn.

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.

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.)

Sol Ring

Arcane Signet

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.

Nuka-Cola Vending Machine

{1}, {T}: Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
Whenever you sacrifice a Food, create a tapped Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Plains

Inspiring Call

Draw a card for each creature you control with a +1/+1 counter on it. Those creatures gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

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.

Breeding Pool

({T}: Add {G} or {U}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Rambunctious Mutt

When this creature enters, destroy target artifact or enchantment an opponent controls.

Tiny

Human

Jaheira, Friend of the Forest

Tokens you control have "{T}: Add {G}."
Choose a Background (You can have a Background as a second commander.)

Windswept Heath

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

Bountiful Promenade

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

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 token: You gain 3 life.")
Sacrifice three Foods: Draw a card.

Gavony Township

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

Rikku, Resourceful Guardian

Whenever you put one or more counters on a creature, until end of turn, that creature can't be blocked by creatures your opponents control.
Steal — {1}, {T}: Move a counter from target creature an opponent controls onto target creature you control. Activate only as a sorcery.

Generous Gift

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

Treasure

{T}, Sacrifice this token: Add one mana of any color.

Farewell

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

Idol of Oblivion

{T}: Draw a card. Activate only if you created a token this turn.
{8}, {T}, Sacrifice this artifact: Create a 10/10 colorless Eldrazi creature token.

Merchant of Truth

Flying
Whenever a nontoken creature you control dies, investigate.
Clues you control have exalted. (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn for each instance of exalted among permanents you control.)

Mushroom Watchdogs

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

Academy Manufactor

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

Damning Verdict

Destroy all creatures with no counters on them.

Loyal Warhound

Vigilance
When this creature enters, if an opponent controls more lands than you, search your library for a basic Plains card, put it onto the battlefield tapped, then shuffle.

Supply Runners

When this creature enters, put a +1/+1 counter on each other creature you control.

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.

Temple Garden

({T}: Add {G} or {W}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Pack Leader

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

Sophia, Dogged Detective

When Sophia 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.

Release the Dogs

Create four 1/1 white Dog creature tokens.

Traveling Botanist

Whenever this creature becomes tapped, look at the top card of your library. If it's a land card, you may reveal it and put it into your hand. If you don't put the card into your hand, you may put it into your graveyard.

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.

Nature's Lore

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

Ongoing Investigation

Whenever one or more creatures you control deal combat damage to a player, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
{1}{G}, Exile a creature card from your graveyard: Investigate. You gain 2 life.

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.

Faithful Watchdog

Vigilance
This creature enters with three +1/+1 counters on it.

Erdwal Illuminator

Flying
Whenever you investigate for the first time each turn, investigate an additional time.

District Mascot

This creature enters with a +1/+1 counter on it.
{1}{G}, Remove two +1/+1 counters from this creature: Destroy target artifact.
Whenever this creature attacks while saddled, put a +1/+1 counter on it.
Saddle 1

Codecracker Hound

When this creature enters, look at the top two cards of your library. Put one into your hand and the other into your graveyard.
Warp {2}{U} (You may cast this card from your hand for its warp cost. Exile this creature at the beginning of the next end step, then you may cast it from exile on a later turn.)

Trusty Retriever

When this creature enters, choose one —
• Put a +1/+1 counter on this creature.
• Return target artifact or enchantment card from your graveyard to your hand.

Evolving Wilds

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

Mirror Entity

Changeling (This card is every creature type.)
{X}: Until end of turn, creatures you control have base power and toughness X/X and gain all creature types.

Lonis, Cryptozoologist

Whenever another nontoken creature you control enters, investigate.
{T}, Sacrifice X Clues: Target opponent reveals the top X cards of their library. You may put a nonland permanent card with mana value X or less from among them onto the battlefield under your control. That player puts the rest on the bottom of their library in a random order.

Selfless Savior

Sacrifice this creature: Another target creature you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Path of Ancestry

This land 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.)

Spirited Companion

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.

Swords to Plowshares

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

Heroic Intervention

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

Exotic Orchard

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

Farseek

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

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}.)