Quasiduplicate

Create a token that's a copy of target creature you control.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Elvish Visionary

When Elvish Visionary enters, draw a card.

Soul Salvage

Return up to two target creature cards from your graveyard to your hand.

Forgotten Ancient

Whenever a player casts a spell, you may put a +1/+1 counter on Forgotten Ancient.
At the beginning of your upkeep, you may move any number of +1/+1 counters from Forgotten Ancient onto other creatures.

Embodiment of Spring

{1}{G}, {T}, Sacrifice Embodiment of Spring: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Mind Flayer

Dominate Monster — When Mind Flayer enters, gain control of target creature for as long as you control Mind Flayer.

Forest

Chupacabra Echo

Fathomless descent — When Chupacabra Echo enters, target creature an opponent controls gets -X/-X until end of turn, where X is the number of permanent cards in your graveyard.

Jungle Hollow

Jungle Hollow enters tapped.
When Jungle Hollow enters, you gain 1 life.
{T}: Add {B} or {G}.

Farhaven Elf

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

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.

Orchard Elemental

Council's dilemma — When Orchard Elemental enters, starting with you, each player votes for sprout or harvest. Put two +1/+1 counters on Orchard Elemental for each sprout vote. You gain 3 life for each harvest vote.

Island

Natural End

Destroy target artifact or enchantment. You gain 3 life.

Mage Hunter

Whenever an opponent casts or copies an instant or sorcery spell, they lose 1 life.

Swamp

Plant

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.

Intellect Devourer

Devour Intellect — When Intellect Devourer enters, each opponent exiles a card from their hand until Intellect Devourer leaves the battlefield.
Body Thief — You may play lands and cast spells from among cards exiled with Intellect Devourer. If you cast a spell this way, you may spend mana as though it were mana of any color to cast it.

Thornwood Falls

Thornwood Falls enters tapped.
When Thornwood Falls enters, you gain 1 life.
{T}: Add {G} or {U}.

Dusk Mangler

As an additional cost to cast this spell, sacrifice a creature, discard a card, or pay 4 life.
When Dusk Mangler enters, each opponent sacrifices a creature, discards a card, and loses 4 life.

Wavesifter

Flying
When Wavesifter enters, investigate twice. (To investigate, create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Evoke {G}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Twisted Embrace

Enchant artifact or creature you control
When Twisted Embrace enters, destroy target creature or planeswalker an opponent controls.
As long as enchanted permanent is a creature, it gets +1/+1.

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.

Ravenous Chupacabra

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

Peregrine Drake

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

Sewer Nemesis

As Sewer Nemesis enters, choose a player.
Sewer Nemesis's power and toughness are each equal to the number of cards in the chosen player's graveyard.
Whenever the chosen player casts a spell, that player mills a card.

Phyrexian Revoker

As Phyrexian Revoker enters, choose a nonland card name.
Activated abilities of sources with the chosen name can't be activated.

Meteor Golem

When Meteor Golem enters, destroy target nonland permanent an opponent controls.

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.

Aethersnipe

When Aethersnipe enters, return target nonland permanent to its owner's hand.
Evoke {1}{U}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Slum Reaper

When Slum Reaper enters, each player sacrifices a creature.

Dismal Backwater

Dismal Backwater enters tapped.
When Dismal Backwater enters, you gain 1 life.
{T}: Add {U} or {B}.

Clue

{2}, Sacrifice this artifact: Draw a card.

Phyrexian Gargantua

When Phyrexian Gargantua enters, you draw two cards and you lose 2 life.

Mana Geode

When Mana Geode enters, scry 1.
{T}: Add one mana of any color.

Psionic Ritual

Replicate—Tap an untapped Horror you control. (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Exile target instant or sorcery card from a graveyard and copy it. You may cast the copy without paying its mana cost.
Exile Psionic Ritual.

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.

Burglar Rat

When Burglar Rat enters, each opponent discards a card.

Exotic Orchard

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

Ghostly Flicker

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

Reflections of Littjara

As Reflections of Littjara enters, choose a creature type.
Whenever you cast a spell of the chosen type, copy that spell. (A copy of a permanent spell becomes a token.)

Arboreal Grazer

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

Dark Hatchling

Flying
When Dark Hatchling enters, destroy target nonblack creature. It can't be regenerated.

Portal of Sanctuary

{1}, {T}: Return target creature you control and each Aura attached to it to their owners' hands. Activate only during your turn.

Yarok's Fenlurker

When Yarok's Fenlurker enters, each opponent exiles a card from their hand.
{2}{B}: Yarok's Fenlurker gets +1/+1 until end of turn.

Soul of the Harvest

Trample
Whenever another nontoken creature you control enters, you may draw a card.

Abyssal Gorestalker

When Abyssal Gorestalker enters, each player sacrifices two creatures.

Bringer of the Last Gift

Flying
When Bringer of the Last Gift enters, if you cast it, each player sacrifices all other creatures they control. Then each player returns all creature cards from their graveyard that weren't put there this way to the battlefield.

Cavalier of Thorns

Reach
When Cavalier of Thorns enters, reveal the top five cards of your library. Put a land card from among them onto the battlefield and the rest into your graveyard.
When Cavalier of Thorns dies, you may exile it. If you do, put another target card from your graveyard on top of your library.

Yarok's Wavecrasher

When Yarok's Wavecrasher enters, return another creature you control to its owner's hand.

Reclamation Sage

When Reclamation Sage enters, you may destroy target artifact or enchantment.

Copy

(This token can be used to represent a token that's a copy of a permanent.)

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 Rager

When Phyrexian Rager enters, you draw a card and you lose 1 life.

Dream Stalker

When Dream Stalker enters, return a permanent you control to its owner's hand.

Dinrova Horror

When Dinrova Horror enters, return target permanent to its owner's hand, then that player discards a card.

Faceless Butcher

When Faceless Butcher enters, exile another target creature.
When Faceless Butcher leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Elder Brain

Menace
Whenever Elder Brain attacks a player, exile all cards from that player's hand, then they draw that many cards. You may play lands and cast spells from among the exiled cards for as long as they remain exiled. If you cast a spell this way, you may spend mana as though it were mana of any color to cast it.

Gravedigger

When Gravedigger enters, you may return target creature card from your graveyard to your hand.

Gluttonous Slug

Menace
Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)

Psychic Symbiont

Flying
When Psychic Symbiont enters, target opponent discards a card and you draw a card.

Rootcoil Creeper

{T}: Add one mana of any color.
{T}: Add two mana of any one color. Spend this mana only to cast spells from your graveyard.
{G}{U}, {T}, Exile Rootcoil Creeper: Return target card with flashback you own from exile to your hand.

Threats Undetected

Search your library for up to four creature cards with different powers and reveal them. An opponent chooses two of those cards. Shuffle the chosen cards into your library and put the rest into your hand.

Radiant Fountain

When Radiant Fountain enters, you gain 2 life.
{T}: Add {C}.

Fertilid

Fertilid enters with two +1/+1 counters on it.
{1}{G}, Remove a +1/+1 counter from Fertilid: Target player searches their library for a basic land card, puts it onto the battlefield tapped, then shuffles.

Springbloom Druid

When Springbloom Druid 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.

Wild Pair

Whenever a creature enters, if you cast it from your hand, you may search your library for a creature card with the same total power and toughness, put it onto the battlefield, then shuffle.

Canopy Baloth

Landfall — Whenever a land you control enters, Canopy Baloth gets +2/+2 until end of turn.

Poison Dart Frog

Reach
{T}: Add one mana of any color.
{2}: Poison Dart Frog gains deathtouch until end of turn.

Grell Philosopher

Aberrant Tinkering — When Grell Philosopher enters and at the beginning of your upkeep, each Horror you control gains all activated abilities of target artifact an opponent controls until end of turn. You may spend blue mana as though it were mana of any color to activate those abilities.