Intruder Alarm

Creatures don't untap during their controllers' untap steps.
Whenever a creature enters the battlefield, untap all creatures.

Joint Exploration

Kicker {G} (You may pay an additional {G} as you cast this spell.)
Scry 2, then draw a card. If this spell was kicked, you may put a land card from your hand onto the battlefield.

Evolution Sage

Landfall — Whenever a land enters the battlefield under your control, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Oversimplify

Exile all creatures. Each player creates a 0/0 green and blue Fractal creature token and puts a number of +1/+1 counters on it equal to the total power of creatures they controlled that were exiled this way.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Fathom Mage

Evolve (Whenever a creature enters the battlefield under your control, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
Whenever a +1/+1 counter is put on Fathom Mage, you may draw a card.

Reef Worm

When Reef Worm dies, create a 3/3 blue Fish creature token with "When this creature dies, create a 6/6 blue Whale creature token with 'When this creature dies, create a 9/9 blue Kraken creature token.'"

Skatewing Spy

{5}{U}: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.)
Each creature you control with a +1/+1 counter on it has flying.

Armorcraft Judge

When Armorcraft Judge enters the battlefield, draw a card for each creature you control with a +1/+1 counter on it.

Master Biomancer

Each other creature you control enters the battlefield with a number of additional +1/+1 counters on it equal to Master Biomancer's power and as a Mutant in addition to its other types.

Timeless Witness

When Timeless Witness enters the battlefield, return target card from your graveyard to your hand.
Eternalize {5}{G}{G} ({5}{G}{G}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a 4/4 black Zombie Human Shaman with no mana cost. Eternalize only as a sorcery.)

Primal Vigor

If one or more tokens would be created, twice that many of those tokens are created instead.
If one or more +1/+1 counters would be put on a creature, twice that many +1/+1 counters are put on that creature instead.

Spidersilk Armor

Creatures you control get +0/+1 and have reach. (They can block creatures with flying.)

Bear Umbra

Enchant creature
Enchanted creature gets +2/+2 and has "Whenever this creature attacks, untap all lands you control."
Totem armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Change of Plans

Each of X target creatures you control connive. You may have any number of them phase out. (To have a creature connive, draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on that creature. Treat phased-out permanents and anything attached to them as though they don't exist until their controller's next turn.)

Garruk's Uprising

When Garruk's Uprising enters the battlefield, if you control a creature with power 4 or greater, draw a card.
Creatures you control have trample. (They can deal excess combat damage to the player or planeswalker they're attacking.)
Whenever a creature with power 4 or greater enters the battlefield under your control, draw a card.

Thrummingbird

Flying
Whenever Thrummingbird deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Verdant Sun's Avatar

Whenever Verdant Sun's Avatar or another creature enters the battlefield under your control, you gain life equal to that creature's toughness.

Champion of Wits

When Champion of Wits enters the battlefield, you may draw cards equal to its power. If you do, discard two cards.
Eternalize {5}{U}{U} ({5}{U}{U}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a 4/4 black Zombie Naga Wizard with no mana cost. Eternalize only as a sorcery.)

Titan Forge

{3}, {T}: Put a charge counter on Titan Forge.
{T}, Remove three charge counters from Titan Forge: Create a 9/9 colorless Golem artifact creature token.

One with the Kami

Flash
Enchant creature you control
Whenever enchanted creature or another modified creature you control dies, create X 1/1 colorless Spirit creature tokens, where X is that creature's power. (Equipment, Auras you control, and counters are modifications.)

Gurgling Anointer

Flying
Whenever you draw your second card each turn, put a +1/+1 counter on Gurgling Anointer.
When Gurgling Anointer dies, return another target creature card with mana value less than or equal to Gurgling Anointer's power from your graveyard to the battlefield.

Araumi of the Dead Tide

{T}, Exile cards from your graveyard equal to the number of opponents you have: Target creature card in your graveyard gains encore until end of turn. The encore cost is equal to its mana cost. (Exile the creature card and pay its mana cost: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Take

Remove all +1/+1 counters from target creature you control. Draw that many cards.
Fuse (You may cast one or both halves of this card from your hand.)

Give

Put three +1/+1 counters on target creature.
Fuse (You may cast one or both halves of this card from your hand.)

Give // Take

Gothmog, Morgul Lieutenant

When Gothmog, Morgul Lieutenant enters the battlefield, amass Orcs 1. (Put a +1/+1 counter on an Army you control. It's also an Orc. If you don't control an Army, create a 0/0 black Orc Army creature token first.)
Creature tokens you control have deathtouch.

Sol Ring

Fertilid

Fertilid enters the battlefield 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.

Supplant Form

Return target creature to its owner's hand. You create a token that's a copy of that creature.

Ordeal of Nylea

Enchant creature
Whenever enchanted creature attacks, put a +1/+1 counter on it. Then if it has three or more +1/+1 counters on it, sacrifice Ordeal of Nylea.
When you sacrifice Ordeal of Nylea, search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Neoform

As an additional cost to cast this spell, 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 with an additional +1/+1 counter on it, then shuffle.

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.

Master Chef

Commander creatures you own have "This creature enters the battlefield with an additional +1/+1 counter on it" and "Other creatures you control enter the battlefield with an additional +1/+1 counter on them."

Crashing Drawbridge

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

Farhaven Elf

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

Elvish Hydromancer

Kicker {3}{U} (You may pay an additional {3}{U} as you cast this spell.)
When Elvish Hydromancer enters the battlefield, if it was kicked, create a token that's a copy of target creature you control.

Silkguard

Put a +1/+1 counter on each of up to X target creatures you control.
Auras, Equipment, and modified creatures you control gain hexproof until end of turn. (Equipment, Auras you control, and counters are modifications.)

Carnivorous Canopy

Destroy target artifact, enchantment, or creature with flying. If that permanent's mana value was 3 or less, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Gavony Unhallowed

Whenever another creature you control dies, put a +1/+1 counter on Gavony Unhallowed.

Mitotic Slime

When Mitotic Slime dies, create two 2/2 green Ooze creature tokens. They have "When this creature dies, create two 1/1 green Ooze creature tokens."

Slip Out the Back

Put a +1/+1 counter on target creature. It phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)

Giant Adephage

Trample
Whenever Giant Adephage deals combat damage to a player, create a token that's a copy of Giant Adephage.

Kami of Whispered Hopes

If one or more +1/+1 counters would be put on a permanent you control, that many plus one +1/+1 counters are put on that permanent instead.
{T}: Add X mana of any one color, where X is Kami of Whispered Hopes's power.

Scale the Heights

Put a +1/+1 counter on up to one target creature. You gain 2 life. You may play an additional land this turn.
Draw a card.

Wrap in Vigor

Primeval Protector

This spell costs {1} less to cast for each creature your opponents control.
When Primeval Protector enters the battlefield, put a +1/+1 counter on each other creature you control.

Freed from the Real

Enchant creature
{U}: Tap enchanted creature.
{U}: Untap enchanted creature.

Tenacious Tomeseeker

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.)
When Tenacious Tomeseeker enters the battlefield, if it was bargained, return target instant or sorcery card from your graveyard to your hand.

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.)

Traverse the Outlands

Search your library for up to X basic land cards, where X is the greatest power among creatures you control. Put those cards onto the battlefield tapped, then shuffle.

Druid's Deliverance

Prevent all combat damage that would be dealt to you this turn. Populate. (Create a token that's a copy of a creature token you control.)

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.

Renata, Called to the Hunt

Renata's power is equal to your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)
Each other creature you control enters the battlefield with an additional +1/+1 counter on it.

Herd Baloth

Whenever one or more +1/+1 counters are put on Herd Baloth, you may create a 4/4 green Beast creature token.

Xavier Sal, Infested Captain

{T}, Remove a counter from another permanent you control: Populate. Activate only as a sorcery. (Create a token that's a copy of a creature token you control.)
{T}, Sacrifice another creature: Proliferate. Activate only as a sorcery. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Reign of the Pit

Each player sacrifices a creature. Create an X/X black Demon creature token with flying, where X is the total power of the creatures sacrificed this way.

Bioshift

Move any number of +1/+1 counters from target creature onto another target creature with the same controller.

Fertile Footsteps

Search your library for a basic land card, put it onto the battlefield, then shuffle. (Then exile this card. You may cast the creature later from exile.)

Beanstalk Giant

Beanstalk Giant's power and toughness are each equal to the number of lands you control.

Beanstalk Giant // Fertile Footsteps

Soulcoil Viper

{B}, {T}, Sacrifice Soulcoil Viper: Return target creature card from your graveyard to the battlefield with a finality counter on it. Activate only as a sorcery. (If a creature with a finality counter on it would die, exile it instead.)

Combine Chrysalis

Creature tokens you control have flying.
{2}{G}{U}, {T}, Sacrifice a token: Create a 4/4 green Beast creature token. Activate only as a sorcery.

Gruff Triplets

Trample
When Gruff Triplets enters the battlefield, if it isn't a token, create two tokens that are copies of it.
When Gruff Triplets dies, put a number of +1/+1 counters equal to its power on each creature you control named Gruff Triplets.

Rampant Rejuvenator

Rampant Rejuvenator enters the battlefield with two +1/+1 counters on it.
When Rampant Rejuvenator dies, search your library for up to X basic land cards, where X is Rampant Rejuvenator's power, put them onto the battlefield, then shuffle.

Priest of the Blood Rite

When Priest of the Blood Rite enters the battlefield, create a 5/5 black Demon creature token with flying.
At the beginning of your upkeep, you lose 2 life.

Ride the Avalanche

The next spell you cast this turn can be cast as though it had flash. When you next cast a spell this turn, put X +1/+1 counters on up to one target creature, where X is the mana value of that spell.

Arboreal Grazer

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

Clone Legion

For each creature target player controls, create a token that's a copy of that creature.