Mountain

Hero of Bretagard

Whenever one or more cards are put into exile from your hand or a spell or ability you control exiles one or more permanents from the battlefield, put that many +1/+1 counters on this creature.
As long as this creature has five or more counters on it, it has flying and is an Angel in addition to its other types.
As long as this creature has ten or more counters on it, it has indestructible and is a God in addition to its other types.

Arena of the Ancients

Legendary creatures don't untap during their controllers' untap steps.
When this artifact enters, tap all legendary creatures.

Jungle Shrine

This land enters tapped.
{T}: Add {R}, {G}, or {W}.

Plains

Shortcut to Mushrooms

When this enchantment enters, the Ring tempts you.
At the beginning of your end step, if a permanent you controlled left the battlefield this turn, put a +1/+1 counter on target creature you control.

Guardian Project

Whenever a nontoken creature you control enters, if it doesn't have the same name as another creature you control or a creature card in your graveyard, draw a card.

Spectator Seating

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

Ninth Bridge Patrol

Whenever another creature you control leaves the battlefield, put a +1/+1 counter on this creature.

Gandalf the White

Flash
You may cast legendary spells and artifact spells as though they had flash.
If a legendary permanent or an artifact entering or leaving the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Prosperous Innkeeper

When this creature enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Whenever another creature you control enters, you gain 1 life.

Suture Priest

Whenever another creature you control enters, you may gain 1 life.
Whenever a creature an opponent controls enters, you may have that player lose 1 life.

Duke Ulder Ravengard

At the beginning of combat on your turn, another target creature you control gains haste and myriad until end of turn. (Whenever it attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Rumor Gatherer

Alliance — Whenever another creature you control enters, scry 1. If this is the second time this ability has resolved this turn, draw a card instead.

Ranger-Captain of Eos

When this creature enters, you may search your library for a creature card with mana value 1 or less, reveal it, put it into your hand, then shuffle.
Sacrifice this creature: Your opponents can't cast noncreature spells this turn.

Norin the Wary

When a player casts a spell or a creature attacks, exile Norin. Return it to the battlefield under its owner's control at the beginning of the next end step.

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.)

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

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.

Warleader's Call

Creatures you control get +1/+1.
Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Genesis Chamber

Whenever a nontoken creature enters, if this artifact is untapped, that creature's controller creates a 1/1 colorless Myr artifact creature token.

Saradoc, Master of Buckland

Whenever Saradoc or another nontoken creature you control with power 2 or less enters, create a 1/1 white Halfling creature token.
Tap two other untapped Halflings you control: Saradoc gets +2/+0 and gains lifelink until end of turn.

Boros Charm

Choose one —
• Boros Charm deals 4 damage to target player or planeswalker.
• Permanents you control gain indestructible until end of turn.
• Target creature gains double strike until end of turn.

Command Tower

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

Guide of Souls

Whenever another creature you control enters, you gain 1 life and get {E} (an energy counter).
Whenever you attack, you may pay {E}{E}{E}. When you do, put two +1/+1 counters and a flying counter on target attacking creature. It becomes an Angel in addition to its other types.

Forest

Bovine Intervention

Destroy target artifact or creature. Its controller creates a 2/2 white Ox creature token.

Gauntlets of Chaos

{5}, Sacrifice this artifact: Exchange control of target artifact, creature, or land you control and target permanent an opponent controls that shares one of those types with it. If those permanents are exchanged this way, destroy all Auras attached to them.

Spire Garden

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

Gala Greeters

Alliance — Whenever another creature you control enters, choose one that hasn't been chosen this turn —
• Put a +1/+1 counter on this creature.
• Create a tapped Treasure token.
• You gain 2 life.

Welcoming Vampire

Flying
Whenever one or more other creatures you control with power 2 or less enter, draw a card. This ability triggers only once each turn.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Nature's Claim

Destroy target artifact or enchantment. Its controller gains 4 life.

Tocasia's Welcome

Whenever one or more creatures you control with mana value 3 or less enter, draw a card. This ability triggers only once each turn.

Boss's Chauffeur

This creature enters with a number of +1/+1 counters on it equal to one plus the number of other creatures you control.
Alliance — Whenever another creature you control enters, put a +1/+1 counter on this creature.
When this creature dies, create a 1/1 green and white Citizen creature token for each +1/+1 counter on it.

Fabled Passage

{T}, Sacrifice this land: 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.

Arcane Signet

Luminous Phantom

Flying
Whenever another creature you control leaves the battlefield, you gain 1 life.
If Luminous Phantom would be put into a graveyard from anywhere, exile it instead.

Lunarch Veteran

Whenever another creature you control enters, you gain 1 life.
Disturb {1}{W} (You may cast this card from your graveyard transformed for its disturb cost.)

Lunarch Veteran // Luminous Phantom

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.

Fellwar Stone

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

Rampant Growth

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

Riftsweeper

When this creature enters, choose target face-up exiled card. Its owner shuffles it into their library.

Case of the Uneaten Feast

Whenever a creature you control enters, you gain 1 life.
To solve — You've gained 5 or more life this turn. (If unsolved, solve at the beginning of your end step.)
Solved — Sacrifice this Case: Creature cards in your graveyard gain "You may cast this card from your graveyard" until end of turn.

Saltskitter

Whenever another creature enters, exile this creature. Return this creature to the battlefield under its owner's control at the beginning of the next end step.

Cosmic Rebirth

Choose target permanent card in your graveyard. If it has mana value 3 or less, you may put it onto the battlefield. If you don't put it onto the battlefield, put it into your hand.
You gain 3 life.

Witty Roastmaster

Alliance — Whenever another creature you control enters, this creature deals 1 damage to each opponent.

Overseer of Vault 76

First Contact — Whenever Overseer of Vault 76 or another creature you control with power 3 or less enters, put a quest counter on Overseer of Vault 76.
At the beginning of combat on your turn, you may remove three quest counters from among permanents you control. When you do, put a +1/+1 counter on each creature you control and they gain vigilance until end of turn.

Cadric, Soul Kindler

The "legend rule" doesn't apply to tokens you control.
Whenever another nontoken legendary permanent you control enters, you may pay {1}. If you do, create a token that's a copy of it. That token gains haste. Sacrifice it at the beginning of the next end step.

Samwise Gamgee

Whenever another nontoken creature you control enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
Sacrifice three Foods: Return target historic card from your graveyard to your hand. (Artifacts, legendaries, and Sagas are historic.)

Sakura-Tribe Elder

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

Farseek

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

Ajani's Welcome

Whenever a creature you control enters, you gain 1 life.

Relic of Legends

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

Rose Room Treasurer

Alliance — Whenever another creature you control enters, create a Treasure token if this is the first or second time this ability has resolved this turn. Otherwise, you may pay {X}. When you do, this creature deals X damage to any target.

Gimli of the Glittering Caves

Double strike
Whenever another legendary creature you control enters, put a +1/+1 counter on Gimli.
Whenever Gimli deals combat damage to a player, create a Treasure token.

Frodo Baggins

Whenever Frodo Baggins or another legendary creature you control enters, the Ring tempts you.
As long as Frodo Baggins is your Ring-bearer, it must be blocked if able.

Angelic Sell-Sword

Flying, vigilance
Whenever this creature or another nontoken creature you control enters, create a 1/1 red Mercenary creature token with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery."
Whenever this creature attacks, if its power is 6 or greater, draw a card.

Helping Hand

Return target creature card with mana value 3 or less from your graveyard to the battlefield tapped.

Auriok Champion

Protection from black and from red
Whenever another creature enters, you may gain 1 life.

Bountiful Promenade

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

Yoshimaru, Ever Faithful

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

Radiant Solar

Flying, lifelink
Whenever this creature or another nontoken creature you control enters, venture into the dungeon. (Enter the first room or advance to the next room.)
{W}, Discard this card: Venture into the dungeon and you gain 3 life.

Blessed Sanctuary

Prevent all noncombat damage that would be dealt to you and creatures you control.
Whenever a nontoken creature you control enters, create a 2/2 white Unicorn creature token.

Legolas Greenleaf

Reach
Legolas can't be blocked by creatures with power 2 or less.
Whenever another legendary creature you control enters, put a +1/+1 counter on Legolas.
Whenever Legolas deals combat damage to a player, draw a card.

Answered Prayers

Whenever a creature you control enters, you gain 1 life. If this enchantment isn't a creature, it becomes a 3/3 Angel creature with flying in addition to its other types until end of turn.

Tibalt's Trickery

Counter target spell. Choose 1, 2, or 3 at random. Its controller mills that many cards, then exiles cards from the top of their library until they exile a nonland card with a different name than that spell. They may cast that card without paying its mana cost. Then they put the exiled cards on the bottom of their library in a random order.

Sol Ring

Crawlspace

No more than two creatures can attack you each combat.

Panharmonicon

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

Thorn Mammoth

Trample
Whenever this creature or another creature you control enters, this creature fights up to one target creature you don't control.

Mace of the Valiant

Equipped creature gets +1/+1 for each charge counter on this Equipment and has vigilance. (Attacking doesn't cause it to tap.)
Whenever a creature you control enters, put a charge counter on this Equipment.
Equip {3}

Crown of Gondor

Equipped creature gets +1/+1 for each creature you control.
When a legendary creature you control enters, if there is no monarch, you become the monarch.
Equip {4}. This ability costs {3} less to activate if you're the monarch.

Sanctum of Eternity

{T}: Add {C}.
{2}, {T}: Return target commander you own from the battlefield to your hand. Activate only during your turn.

Rocco, Cabaretti Caterer

When Rocco enters, if you cast it, you may search your library for a creature card with mana value X or less, put it onto the battlefield, then shuffle.

Aura Shards

Whenever a creature you control enters, you may destroy target artifact or enchantment.

Confusion in the Ranks

Whenever an artifact, creature, or enchantment enters, its controller chooses target permanent another player controls that shares a card type with it. Exchange control of those permanents.