Ulvenwald Hydra

Reach
Ulvenwald Hydra's power and toughness are each equal to the number of lands you control.
When Ulvenwald Hydra enters, you may search your library for a land card, put it onto the battlefield tapped, then shuffle.

Breeding Pool

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

Prime Speaker Zegana

Prime Speaker Zegana enters with X +1/+1 counters on it, where X is the greatest power among other creatures you control.
When Prime Speaker Zegana enters, draw cards equal to its power.

Watery Grave

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

Sunken Hollow

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

Phantasmal Image

You may have Phantasmal Image enter as a copy of any creature on the battlefield, except it's an Illusion in addition to its other types and it has "When this creature becomes the target of a spell or ability, sacrifice it."

Temple of Deceit

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 {U} or {B}.

Springbloom Druid

When this creature enters, you may sacrifice a land. If you do, search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Mulldrifter

Flying
When Mulldrifter enters, draw two cards.
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Phyrexian Delver

When Phyrexian Delver enters, return target creature card from your graveyard to the battlefield. You lose life equal to that card's mana value.

Exotic Orchard

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

Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Temur Sabertooth

{1}{G}: You may return another creature you control to its owner's hand. If you do, Temur Sabertooth gains indestructible until end of turn.

Overgrown Tomb

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

Acidic Slime

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When Acidic Slime enters, destroy target artifact, enchantment, or land.

Swamp

Massacre Wurm

When this creature enters, creatures your opponents control get -2/-2 until end of turn.
Whenever a creature an opponent controls dies, that player loses 2 life.

Farhaven Elf

When Farhaven Elf enters, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Thespian's Stage

{T}: Add {C}.
{2}, {T}: Thespian's Stage becomes a copy of target land, except it has this ability.

Golgari Signet

Conjurer's Closet

At the beginning of your end step, you may exile target creature you control, then return that card to the battlefield under your control.

Ravenous Chupacabra

When Ravenous Chupacabra enters, destroy target creature an opponent controls.

Elvish Visionary

When Elvish Visionary enters, draw a card.

Hostage Taker

When Hostage Taker enters, exile another target creature or artifact until Hostage Taker leaves the battlefield. You may cast that card for as long as it remains exiled, and mana of any type can be spent to cast that spell.

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Coiling Oracle

When Coiling Oracle enters, reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put that card into your hand.

Lotus Cobra

Landfall — Whenever a land you control enters, add one mana of any color.

Craterhoof Behemoth

Haste
When Craterhoof Behemoth enters, creatures you control gain trample and get +X/+X until end of turn, where X is the number of creatures you control.

Counterspell

Snow-Covered Forest

Illusionist's Stratagem

Exile up to two target creatures you control, then return those cards to the battlefield under their owner's control.
Draw a card.

Woodland Cemetery

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

Llanowar Wastes

{T}: Add {C}.
{T}: Add {B} or {G}. Llanowar Wastes deals 1 damage to you.

City of Brass

Whenever City of Brass becomes tapped, it deals 1 damage to you.
{T}: Add one mana of any color.

Snow-Covered Island

Morphic Pool

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

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Eternal Witness

When Eternal Witness enters, you may return target card from your graveyard to your hand.

Birthing Pod

({G/P} can be paid with either {G} or 2 life.)
{1}{G/P}, {T}, Sacrifice a creature: Search your library for a creature card with mana value equal to 1 plus the sacrificed creature's mana value, put that card onto the battlefield, then shuffle. Activate only as a sorcery.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Bojuka Bog

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

Gonti, Lord of Luxury

Deathtouch
When Gonti, Lord of Luxury enters, look at the top four cards of target opponent's library, exile one of them face down, then put the rest on the bottom of that library in a random order. You may cast that card for as long as it remains exiled, and mana of any type can be spent to cast that spell.

Cloud of Faeries

Flying
When Cloud of Faeries enters, untap up to two lands.
Cycling {2} ({2}, Discard this card: Draw a card.)

Peregrine Drake

Flying
When Peregrine Drake enters, untap up to five lands.

Sol Ring

Avenger of Zendikar

When Avenger of Zendikar enters, create a 0/1 green Plant creature token for each land you control.
Landfall — Whenever a land you control enters, you may put a +1/+1 counter on each Plant creature you control.

Command Tower

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

Rune-Scarred Demon

Flying
When this creature enters, search your library for a card, put it into your hand, then shuffle.

Yarok, the Desecrated

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

Spark Double

You may have Spark Double enter as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Yavimaya Coast

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

Snow-Covered Swamp

Risen Reef

Whenever Risen Reef or another Elemental you control enters, look at the top card of your library. If it's a land card, you may put it onto the battlefield tapped. If you don't put the card onto the battlefield, put it into your hand.

Wall of Blossoms

Defender
When Wall of Blossoms enters, draw a card.

Agent of Treachery

When Agent of Treachery enters, gain control of target permanent.
At the beginning of your end step, if you control three or more permanents you don't own, draw three cards.

Tatyova, Benthic Druid

Landfall — Whenever a land you control enters, you gain 1 life and draw a card.

Panharmonicon

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

Cloudstone Curio

Whenever a nonartifact permanent you control enters, you may return another permanent you control that shares a permanent type with it to its owner's hand.

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}.

Reliquary Tower

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

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Rite of Replication

Kicker {5} (You may pay an additional {5} as you cast this spell.)
Create a token that's a copy of target creature. If this spell was kicked, create five of those tokens instead.

Sire of Stagnation

Devoid (This card has no color.)
Whenever a land an opponent controls enters, that player exiles the top two cards of their library and you draw two cards.

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Forest

Assassin's Trophy

Destroy target permanent an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Island

Underground River

{T}: Add {C}.
{T}: Add {U} or {B}. Underground River deals 1 damage to you.

Sylvan Library

At the beginning of your draw step, you may draw two additional cards. If you do, choose two cards in your hand drawn this turn. For each of those cards, pay 4 life or put the card on top of your library.

The Great Henge

This spell costs {X} less to cast, where X is the greatest power among creatures you control.
{T}: Add {G}{G}. You gain 2 life.
Whenever a nontoken creature you control enters, put a +1/+1 counter on it and draw a card.

Arboreal Grazer

Reach
When Arboreal Grazer enters, you may put a land card from your hand onto the battlefield tapped.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Ghostly Flicker

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Hinterland Harbor

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

Baleful Strix

Flying, deathtouch
When Baleful Strix enters, draw a card.

Drowned Catacomb

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

Zendikar's Roil

Landfall — Whenever a land you control enters, create a 2/2 green Elemental creature token.

Noxious Gearhulk

Menace
When Noxious Gearhulk enters, you may destroy another target creature. If a creature is destroyed this way, you gain life equal to its toughness.

Reclamation Sage

When this creature enters, you may destroy target artifact or enchantment.

Bramble Sovereign

Whenever another nontoken creature enters, you may pay {1}{G}. If you do, that creature's controller creates a token that's a copy of that creature.

Dimir Signet

Temple of Malady

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 {B} or {G}.

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.

Treachery

Enchant creature
When Treachery enters, untap up to five lands.
You control enchanted creature.

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.

Muldrotha, the Gravetide

During each of your turns, you may play a land and cast a permanent spell of each permanent type from your graveyard. (If a card has multiple permanent types, choose one as you play it.)

Swan Song

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

Field of the Dead

Field of the Dead enters tapped.
{T}: Add {C}.
Whenever Field of the Dead or another land you control enters, if you control seven or more lands with different names, create a 2/2 black Zombie creature token.

Wood Elves

When Wood Elves enters, search your library for a Forest card, put that card onto the battlefield, then shuffle.

Deadeye Navigator

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Deadeye Navigator is paired with another creature, each of those creatures has "{1}{U}: Exile this creature, then return it to the battlefield under your control."

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Fierce Empath

When this creature enters, you may search your library for a creature card with mana value 6 or greater, reveal it, put it into your hand, then shuffle.

Simic Signet

Venser, Shaper Savant

Flash (You may cast this spell any time you could cast an instant.)
When Venser, Shaper Savant enters, return target spell or permanent to its owner's hand.