Chasm Skulker

Whenever you draw a card, put a +1/+1 counter on this creature.
When this creature dies, create X 1/1 blue Squid creature tokens with islandwalk, where X is the number of +1/+1 counters on this creature. (They can't be blocked as long as defending player controls an Island.)

Adrix and Nev, Twincasters

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
If one or more tokens would be created under your control, twice that many of those tokens are created instead.

Beastmaster Ascension

Whenever a creature you control attacks, you may put a quest counter on this enchantment.
As long as this enchantment has seven or more quest counters on it, creatures you control get +5/+5.

Replicating Ring

{T}: Add one mana of any color.
At the beginning of your upkeep, put a night counter on this artifact. Then if it has eight or more night counters on it, remove all of them and create eight colorless snow artifact tokens named Replicated Ring with "{T}: Add one mana of any color."

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Hydra Broodmaster

{X}{X}{G}: Monstrosity X. (If this creature isn't monstrous, put X +1/+1 counters on it and it becomes monstrous.)
When this creature becomes monstrous, create X X/X green Hydra creature tokens.

Simic Growth Chamber

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {G}{U}.

Rampaging Baloths

Trample
Landfall — Whenever a land you control enters, you may create a 4/4 green Beast creature token.

Stolen by the Fae

Return target creature with mana value X to its owner's hand. You create X 1/1 blue Faerie creature tokens with flying.

Risen Reef

Whenever this creature 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.

Simic Signet

Parallel Evolution

For each creature token on the battlefield, its controller creates a token that's a copy of that creature.
Flashback {4}{G}{G}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.

Birds of Paradise

Agent of Treachery

When this creature 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.

Acidic Slime

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

Kodama's Reach

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.

Avenger of Zendikar

When this creature 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.

Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

Thought Vessel

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

Sakura-Tribe Elder

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

Jaheira, Friend of the Forest

Tokens you control have "{T}: Add {G}."
Choose a Background (You can have a Background as a second commander.)

Deep Forest Hermit

Vanishing 3 (This creature enters with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When this creature enters, create four 1/1 green Squirrel creature tokens.
Squirrels you control get +1/+1.

Man-o'-War

When this creature enters, return target creature to its owner's hand.

Double Major

Copy target creature spell you control, except it isn't legendary if the spell is legendary. (A copy of a creature spell becomes a token.)

Negate

Trygon Predator

Flying
Whenever this creature deals combat damage to a player, you may destroy target artifact or enchantment that player controls.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Reclamation Sage

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

Spell Swindle

Counter target spell. Create X Treasure tokens, where X is that spell's mana value. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Krosan Grip

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Destroy target artifact or enchantment.

Awaken the Woods

Create X 1/1 green Forest Dryad land creature tokens. (They're affected by summoning sickness.)

Rampant Growth

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

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Timestream Navigator

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
{2}{U}{U}, {T}, Put this creature on the bottom of its owner's library: Take an extra turn after this one. Activate only if you have the city's blessing.

Curiosity Crafter

Flying
You have no maximum hand size.
Whenever a creature token you control deals combat damage to a player, draw a card.

Craterhoof Behemoth

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

Island

Guardian Augmenter

Flash
Commander creatures you control get +2/+2.
Commanders you control have hexproof.

Coiling Oracle

When this creature 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.

Counterspell

Panharmonicon

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

Master of Waves

Protection from red
Elemental creatures you control get +1/+1.
When this creature enters, create a number of 1/0 blue Elemental creature tokens equal to your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Canoptek Scarab Swarm

Flying
Feeder Mandibles — When this creature enters, exile target player's graveyard. For each artifact or land card exiled this way, create a 1/1 colorless Insect artifact creature token with flying.

Myr Battlesphere

When this creature enters, create four 1/1 colorless Myr artifact creature tokens.
Whenever this creature attacks, you may tap X untapped Myr you control. If you do, this creature gets +X/+0 until end of turn and deals X damage to the player or planeswalker it's attacking.

Command Tower

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

Somberwald Sage

{T}: Add three mana of any one color. Spend this mana only to cast creature spells.

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, this artifact deals 3 damage to you.
{T}: Add {C}{C}.

Garruk, Primal Hunter

+1: Create a 3/3 green Beast creature token.
−3: Draw cards equal to the greatest power among creatures you control.
−6: Create a 6/6 green Wurm creature token for each land you control.

Hinterland Harbor

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

Lightning Greaves

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

Llanowar Elves

Extravagant Replication

At the beginning of your upkeep, create a token that's a copy of another target nonland permanent you control.

Forest

Aether Mutation

Return target creature to its owner's hand. Create X 1/1 green Saproling creature tokens, where X is that creature's mana value.

Hornet Queen

Flying, deathtouch
When this creature enters, create four 1/1 green Insect creature tokens with flying and deathtouch.

Jeweled Lotus

{T}, Sacrifice this artifact: Add three mana of any one color. Spend this mana only to cast your commander.

Second Harvest

For each token you control, create a token that's a copy of that permanent.

Wood Elves

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

Pest Infestation

Destroy up to X target artifacts and/or enchantments. Create twice X 1/1 black and green Pest creature tokens with "When this token dies, you gain 1 life."

Kruphix, God of Horizons

Indestructible
As long as your devotion to green and blue is less than seven, Kruphix isn't a creature.
You have no maximum hand size.
If you would lose unspent mana, that mana becomes colorless instead.

Sol Ring

Misty Rainforest

{T}, Pay 1 life, Sacrifice this land: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

Biovisionary

At the beginning of the end step, if you control four or more creatures named Biovisionary, you win the game.

Elvish Visionary

Esix, Fractal Bloom

Flying
The first time you would create one or more tokens during each of your turns, you may instead choose a creature other than Esix and create that many tokens that are copies of that creature.

Scute Swarm

Landfall — Whenever a land you control enters, create a 1/1 green Insect creature token. If you control six or more lands, create a token that's a copy of this creature instead.

Circle of Dreams Druid

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

Botanical Sanctum

This land enters tapped unless you control two or fewer other lands.
{T}: Add {G} or {U}.

Dreamroot Cascade

This land enters tapped unless you control two or more other lands.
{T}: Add {G} or {U}.

Ezuri's Predation

For each creature your opponents control, create a 4/4 green Phyrexian Beast creature token. Each of those tokens fights a different one of those creatures.