Find the Path

Enchant land
When Find the Path enters the battlefield, venture into the dungeon. (Enter the first room or advance to the next room.)
Enchanted land has "{T}: Add {G}{G}."

Aarakocra Sneak

Flying
When Aarakocra Sneak enters the battlefield, you take the initiative.

Rilsa Rael, Kingpin

Deathtouch
When Rilsa Rael, Kingpin enters the battlefield, you take the initiative.
Whenever you attack, target attacking creature gains deathtouch until end of turn. If you've completed a dungeon, that creature also gets +5/+0 and gains first strike and menace until end of turn.

Drowned Catacomb

Drowned Catacomb enters the battlefield tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Dreamroot Cascade

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

Sarevok's Tome

When Sarevok's Tome enters the battlefield, you take the initiative.
{T}: Add {C}. If you have the initiative, add {C}{C} instead.
{3}, {T}: Exile cards from the top of your library until you exile a nonland card. You may cast that card without paying its mana cost. Activate only if you've completed a dungeon.

Underdark Explorer

Menace (This creature can't be blocked except by two or more creatures.)
When Underdark Explorer enters the battlefield, you take the initiative.

Command Tower

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

Otawara, Soaring City

{T}: Add {U}.
Channel — {3}{U}, Discard Otawara, Soaring City: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs {1} less to activate for each legendary creature you control.

Demolition Field

{T}: Add {C}.
{2}, {T}, Sacrifice Demolition Field: Destroy target nonbasic land an opponent controls. That land's controller may search their library for a basic land card, put it onto the battlefield, then shuffle. You may search your library for a basic land card, put it onto the battlefield, then shuffle.

Yarok, the Desecrated

Deathtouch, lifelink
If a permanent entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Forest

Zagoth Triome

({T}: Add {B}, {G}, or {U}.)
Zagoth Triome enters the battlefield tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Exotic Orchard

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

Acererak the Archlich

When Acererak the Archlich enters the battlefield, if you haven't completed Tomb of Annihilation, return Acererak the Archlich to its owner's hand and venture into the dungeon.
Whenever Acererak the Archlich attacks, for each opponent, you create a 2/2 black Zombie creature token unless that player sacrifices a creature.

Feywild Caretaker

When Feywild Caretaker enters the battlefield, you take the initiative.
At the beginning of your end step, if you have the initiative, create a 1/1 blue Faerie Dragon creature token with flying.

Morphic Pool

Morphic Pool enters the battlefield tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

Rejuvenating Springs

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

Tomb of Horrors Adventurer

When Tomb of Horrors Adventurer enters the battlefield, you take the initiative.
Whenever you cast your second spell each turn, copy it. If you've completed a dungeon, copy that spell twice instead. You may choose new targets for the copies. (A copy of a permanent spell becomes a token.)

Shipwreck Marsh

Shipwreck Marsh enters the battlefield tapped unless you control two or more other lands.
{T}: Add {U} or {B}.

Sunken Hollow

({T}: Add {U} or {B}.)
Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.

Avenging Hunter

Trample
When Avenging Hunter enters the battlefield, you take the initiative.

Passageway Seer

Lifelink
When Passageway Seer enters the battlefield, you take the initiative.
At the beginning of your end step, if you have the initiative, put a +1/+1 counter on Passageway Seer.

Bojuka Bog

Bojuka Bog enters the battlefield tapped.
When Bojuka Bog enters the battlefield, exile target player's graveyard.
{T}: Add {B}.

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.

Deathcap Glade

Deathcap Glade enters the battlefield tapped unless you control two or more other lands.
{T}: Add {B} or {G}.

Takenuma, Abandoned Mire

{T}: Add {B}.
Channel — {3}{B}, Discard Takenuma, Abandoned Mire: Mill three cards, then return a creature or planeswalker card from your graveyard to your hand. This ability costs {1} less to activate for each legendary creature you control.

Undermountain Adventurer

Vigilance
When Undermountain Adventurer enters the battlefield, you take the initiative.
{T}: Add {G}{G}. If you've completed a dungeon, add six {G} instead.

Opulent Palace

Opulent Palace enters the battlefield tapped.
{T}: Add {B}, {G}, or {U}.

Precipitous Drop

Enchant creature
When Precipitous Drop enters the battlefield, venture into the dungeon. (Enter the first room or advance to the next room.)
Enchanted creature gets -2/-2. It gets -5/-5 instead as long as you've completed a dungeon.

Undergrowth Stadium

Undergrowth Stadium enters the battlefield tapped unless you have two or more opponents.
{T}: Add {B} or {G}.

Swamp

Island

Woodland Cemetery

Woodland Cemetery enters the battlefield tapped unless you control a Swamp or a Forest.
{T}: Add {B} or {G}.

Displacer Beast

When Displacer Beast enters the battlefield, venture into the dungeon. (Enter the first room or advance to the next room.)
Displacement — {3}{U}: Return Displacer Beast to its owner's hand.

Trailblazer's Torch

When Trailblazer's Torch enters the battlefield, you take the initiative.
Whenever equipped creature becomes blocked, it deals 2 damage to each creature blocking it.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Hinterland Harbor

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

Ravenloft Adventurer

When Ravenloft Adventurer enters the battlefield, you take the initiative.
If a creature an opponent controls would die, instead exile it and put a hit counter on it.
Whenever Ravenloft Adventurer attacks, if you've completed a dungeon, defending player loses 1 life for each card they own in exile with a hit counter on it.

Dungeon Delver

Commander creatures you own have "Room abilities of dungeons you own trigger an additional time."

Vicious Battlerager

When Vicious Battlerager enters the battlefield, you take the initiative.
Spiked Retribution — Whenever Vicious Battlerager becomes blocked by a creature, that creature's controller loses 5 life.