Panharmonicon

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

Court of Ardenvale

When Court of Ardenvale enters, you become the monarch.
At the beginning of your upkeep, return target permanent card with mana value 3 or less from your graveyard to your hand. If you're the monarch, return that permanent card to the battlefield instead.

Spara's Headquarters

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

Access Tunnel

{T}: Add {C}.
{3}, {T}: Target creature with power 3 or less can't be blocked this turn.

Hover Barrier

Charix, the Raging Isle

Spells your opponents cast that target Charix, the Raging Isle cost {2} more to cast.
{3}: Charix gets +X/-X until end of turn, where X is the number of Islands you control.

Counterspell

Lightning Greaves

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

Bar the Door

Creatures you control get +0/+4 until end of turn.

Hinterland Harbor

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

Vine Trellis

Defender (This creature can't attack.)
{T}: Add {G}.

Carven Caryatid

Defender (This creature can't attack.)
When Carven Caryatid enters, draw a card.

Weathered Sentinels

Defender, vigilance, reach, trample
Weathered Sentinels can attack players who attacked you during their last turn as though it didn't have defender.
Whenever Weathered Sentinels attacks, it gets +3/+3 and gains indestructible until end of turn.

Wall of Junk

Defender (This creature can't attack.)
When Wall of Junk blocks, return it to its owner's hand at end of combat. (Return it only if it's on the battlefield.)

Stalwart Shield-Bearers

Defender
Other creatures you control with defender get +0/+2.

Rampant Growth

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

Slagwurm Armor

Equipped creature gets +0/+6.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery. This card enters unattached and stays on the battlefield if the creature leaves.)

Brave the Sands

Creatures you control have vigilance.
Each creature you control can block an additional creature each combat.

Wall of Denial

Defender, flying
Shroud (This creature can't be the target of spells or abilities.)

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.

Island

Expel the Interlopers

Choose a number between 0 and 10. Destroy all creatures with power greater than or equal to the chosen number.

Tetsuko Umezawa, Fugitive

Creatures you control with power or toughness 1 or less can't be blocked.

Exotic Orchard

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

Angelic Wall

Defender (This creature can't attack.)
Flying

Negate

Wall of Frost

Defender
Whenever Wall of Frost blocks a creature, that creature doesn't untap during its controller's next untap step.

Huatli, the Sun's Heart

Each creature you control assigns combat damage equal to its toughness rather than its power.
−3: You gain life equal to the greatest toughness among creatures you control.

Rolling Stones

Wall creatures can attack as though they didn't have defender.

Sol Ring

Mnemonic Wall

Defender
When Mnemonic Wall enters, you may return target instant or sorcery card from your graveyard to your hand.

Assault Formation

Each creature you control assigns combat damage equal to its toughness rather than its power.
{G}: Target creature with defender can attack this turn as though it didn't have defender.
{2}{G}: Creatures you control get +0/+1 until end of turn.

Forest

Tower Defense

Creatures you control get +0/+5 and gain reach until end of turn.

Seaside Citadel

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

Terramorphic Expanse

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

Prairie Stream

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

Wall of Omens

Defender
When Wall of Omens enters, draw a card.

Stoneskin

Flash
Enchant creature
Enchanted creature gets +0/+10.

Crashing Drawbridge

Defender
{T}: Creatures you control gain haste until end of turn.

Jeskai Barricade

Flash (You may cast this spell any time you could cast an instant.)
Defender
When Jeskai Barricade enters, you may return another target creature you control to its owner's hand.

Angelic Chorus

Whenever a creature you control enters, you gain life equal to its toughness.

Towering Titan

Towering Titan enters with X +1/+1 counters on it, where X is the total toughness of other creatures you control.
Sacrifice a creature with defender: All creatures gain trample until end of turn.

Riptide Turtle

Fell the Mighty

Destroy all creatures with power greater than target creature's power.

Delney, Streetwise Lookout

Creatures you control with power 2 or less can't be blocked by creatures with power 3 or greater.
If an ability of a creature you control with power 2 or less triggers, that ability triggers an additional time.

Fortified Rampart

The Pride of Hull Clade

This spell costs {X} less to cast, where X is the total toughness of creatures you control.
Defender
{2}{U}{U}: Until end of turn, target creature you control gets +1/+0, gains "Whenever this creature deals combat damage to a player, draw cards equal to its toughness," and can attack as though it didn't have defender.

Bedrock Tortoise

During your turn, creatures you control have hexproof.
Each creature you control with toughness greater than its power assigns combat damage equal to its toughness rather than its power.

Evolving Wilds

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

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.

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

Wingmantle Chaplain

Defender
When Wingmantle Chaplain enters, create a 1/1 white Bird creature token with flying for each creature with defender you control.
Whenever another creature you control with defender enters, create a 1/1 white Bird creature token with flying.

Walking Bulwark

Defender
{2}: Until end of turn, target creature with defender gains haste, can attack as though it didn't have defender, and assigns combat damage equal to its toughness rather than its power. Activate only as a sorcery.

High Alert

Each creature you control assigns combat damage equal to its toughness rather than its power.
Creatures you control can attack as though they didn't have defender.
{2}{W}{U}: Untap target creature.

Eerie Interlude

Exile any number of target creatures you control. Return those cards to the battlefield under their owner's control at the beginning of the next end step.

Axebane Guardian

Defender
{T}: Add X mana in any combination of colors, where X is the number of creatures you control with defender.

Generous Gift

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

Flumph

Defender, flying
Whenever Flumph is dealt damage, you and target opponent each draw a card.

Jungle Barrier

Defender (This creature can't attack.)
When Jungle Barrier enters, draw a card.

Beast Within

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

Dawn

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Return all creature cards with power 2 or less from your graveyard to your hand.

Dusk

Destroy all creatures with power 3 or greater.

Dusk // Dawn

Wall of Glare

Defender (This creature can't attack.)
Wall of Glare can block any number of creatures.

Fog Bank

Defender (This creature can't attack.)
Flying
Prevent all combat damage that would be dealt to and dealt by this creature.

Guard Gomazoa

Defender, flying
Prevent all combat damage that would be dealt to Guard Gomazoa.

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.

Farseek

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

Wall of Stolen Identity

You may have Wall of Stolen Identity enter as a copy of any creature on the battlefield, except it's a Wall in addition to its other types and has defender. When you do, tap the copied creature and it doesn't untap during its controller's untap step for as long as you control Wall of Stolen Identity.

Sunscape Familiar

Defender (This creature can't attack.)
Green spells and blue spells you cast cost {1} less to cast.

Sunpetal Grove

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

Overgrown Battlement

Defender
{T}: Add {G} for each creature you control with defender.

Perimeter Captain

Defender
Whenever a creature you control with defender blocks, you may gain 2 life.

Rammas Echor, Ancient Shield

Whenever you cast your second spell each turn, draw a card, then create a 0/3 white Wall creature token with defender.
At the beginning of combat on your turn, creatures you control with defender gain exalted until end of turn. (Whenever a creature you control attacks alone, it gets +1/+1 until end of turn for each instance of exalted among permanents you control.)

Command Tower

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

Plains

Canopy Vista

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

Shield-Wall Sentinel

Defender
When Shield-Wall Sentinel enters, you may search your library for a creature card with defender, reveal it, put it into your hand, then shuffle.

Glacial Fortress

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

Zopandrel, Hunger Dominus

Reach
At the beginning of each combat, double the power and toughness of each creature you control until end of turn.
{G/P}{G/P}, Sacrifice two other creatures: Put an indestructible counter on Zopandrel, Hunger Dominus. ({G/P} can be paid with either {G} or 2 life.)

Arcades, the Strategist

Flying, vigilance
Whenever a creature you control with defender enters, draw a card.
Each creature you control with defender assigns combat damage equal to its toughness rather than its power and can attack as though it didn't have defender.

Robe of Stars

Equipped creature gets +0/+3.
Astral Projection — {1}{W}: Equipped creature phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)
Equip {1}

Last March of the Ents

This spell can't be countered.
Draw cards equal to the greatest toughness among creatures you control, then put any number of creature cards from your hand onto the battlefield.