Chatterstorm

Create a 1/1 green Squirrel creature token.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Swamp

Deep Forest Hermit

Vanishing 3 (This creature enters the battlefield 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 Deep Forest Hermit enters the battlefield, create four 1/1 green Squirrel creature tokens.
Squirrels you control get +1/+1.

Black Cat

When Black Cat dies, target opponent discards a card at random.

Druid's Call

Enchant creature
Whenever enchanted creature is dealt damage, its controller creates that many 1/1 green Squirrel creature tokens.

Mountain

Arcbound Mouser

Lifelink
Modular 1 (This creature enters the battlefield with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Jinnie Fay, Jetmir's Second

If you would create one or more tokens, you may instead create that many 2/2 green Cat creature tokens with haste or that many 3/1 green Dog creature tokens with vigilance.

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.

Squirrel Wrangler

{1}{G}, Sacrifice a land: Create two 1/1 green Squirrel creature tokens.
{1}{G}, Sacrifice a land: Squirrel creatures get +1/+1 until end of turn.

Second Harvest

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

Adorable Kitten

When this creature enters the battlefield, roll a six-sided die. You gain life equal to the result.

Aetherwind Basker

Trample
Whenever Aetherwind Basker enters the battlefield or attacks, you get {E} (an energy counter) for each creature you control.
Pay {E}: Aetherwind Basker gets +1/+1 until end of turn.

Owlbear Cub

Mama's Coming — Whenever Owlbear Cub attacks a player who controls eight or more lands, look at the top eight cards of your library. You may put a creature card from among them onto the battlefield tapped and attacking that player. Put the rest on the bottom of your library in a random order.

Plains

Affectionate Indrik

When Affectionate Indrik enters the battlefield, you may have it fight target creature you don't control. (Each deals damage equal to its power to the other.)

Squirrel Mob

Squirrel Mob gets +1/+1 for each other Squirrel on the battlefield.

Scurry Oak

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 one or more +1/+1 counters are put on Scurry Oak, you may create a 1/1 green Squirrel creature token.

Sylvan Anthem

Green creatures you control get +1/+1.
Whenever a green creature enters the battlefield under your control, scry 1.

Hyalopterous Lemure

{0}: Hyalopterous Lemure gets -1/-0 and gains flying until end of turn.

Arcane Signet

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

Rin and Seri, Inseparable

Whenever you cast a Dog spell, create a 1/1 green Cat creature token.
Whenever you cast a Cat spell, create a 1/1 white Dog creature token.
{R}{G}{W}, {T}: Rin and Seri, Inseparable deals damage to any target equal to the number of Dogs you control. You gain life equal to the number of Cats you control.

Colossification

Enchant creature
When Colossification enters the battlefield, tap enchanted creature.
Enchanted creature gets +20/+20.

Leonin Warleader

Whenever Leonin Warleader attacks, create two 1/1 white Cat creature tokens with lifelink that are tapped and attacking.

Chatterfang, Squirrel General

Forestwalk (This creature can't be blocked as long as defending player controls a Forest.)
If one or more tokens would be created under your control, those tokens plus that many 1/1 green Squirrel creature tokens are created instead.
{B}, Sacrifice X Squirrels: Target creature gets +X/-X until end of turn.

Bellowing Elk

As long as you had another creature enter the battlefield under your control this turn, Bellowing Elk has trample and indestructible.

Aggressive Mammoth

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Other creatures you control have trample.

Golgari Signet

Heroic Intervention

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

Jegantha, the Wellspring

Companion — No card in your starting deck has more than one of the same mana symbol in its mana cost. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
{T}: Add {W}{U}{B}{R}{G}. This mana can't be spent to pay generic mana costs.

Ashcoat Bear

Flash (You may cast this spell any time you could cast an instant.)

Deranged Hermit

Echo {3}{G}{G} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Deranged Hermit enters the battlefield, create four 1/1 green Squirrel creature tokens.
Squirrel creatures get +1/+1.

Timeless Lotus

Timeless Lotus enters the battlefield tapped.
{T}: Add {W}{U}{B}{R}{G}.

Drey Keeper

When Drey Keeper enters the battlefield, create two 1/1 green Squirrel creature tokens.
{3}{B}: Squirrels you control get +1/+0 and gain menace until end of turn.

Mother Bear

{3}{G}{G}, Exile Mother Bear from your graveyard: Create two 2/2 green Bear creature tokens. Activate only as a sorcery.

Aetherstream Leopard

Trample
When Aetherstream Leopard enters the battlefield, you get {E} (an energy counter).
Whenever Aetherstream Leopard attacks, you may pay {E}. If you do, it gets +2/+0 until end of turn.

Cultural Exchange

Choose any number of creatures target player controls. Choose the same number of creatures another target player controls. Those players exchange control of those creatures. (This effect lasts indefinitely.)

Alpine Watchdog

Vigilance (Attacking doesn't cause this creature to tap.)

Furnace Whelp

Flying
{R}: Furnace Whelp gets +1/+0 until end of turn.

Talisman of Resilience

{T}: Add {C}.
{T}: Add {B} or {G}. Talisman of Resilience deals 1 damage to you.

Lulu, Loyal Hollyphant

Flying
At the beginning of your end step, if a permanent you controlled left the battlefield this turn, put a +1/+1 counter on each tapped creature you control, then untap them.
Choose a Background (You can have a Background as a second commander.)

Tribute to the World Tree

Whenever a creature enters the battlefield under your control, draw a card if its power is 3 or greater. Otherwise, put two +1/+1 counters on it.

Chitterspitter

At the beginning of your upkeep, you may sacrifice a token. If you do, put an acorn counter on Chitterspitter.
Squirrels you control get +1/+1 for each acorn counter on Chitterspitter.
{G}, {T}: Create a 1/1 green Squirrel creature token.

Birds of Paradise

Wild Dogs

At the beginning of your upkeep, if a player has more life than each other player, the player with the most life gains control of Wild Dogs.
Cycling {2} ({2}, Discard this card: Draw a card.)

Poison-Tip Archer

Reach (This creature can block creatures with flying.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Whenever another creature dies, each opponent loses 1 life.

Yavimaya, Cradle of Growth

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

The Shire

The Shire enters the battlefield tapped unless you control a legendary creature.
{T}: Add {G}.
{1}{G}, {T}, Tap an untapped creature you control: Create a Food token.

Scurrid Colony

Reach
Scurrid Colony gets +2/+2 as long as you control eight or more lands.

Fellwar Stone

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

Jaheira, Friend of the Forest

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

Steppe Lynx

Landfall — Whenever a land enters the battlefield under your control, Steppe Lynx gets +2/+2 until end of turn.

Circle of Dreams Druid

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

Eternal Witness

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

Thriving Grubs

When Thriving Grubs enters the battlefield, you get {E}{E} (two energy counters).
Whenever Thriving Grubs attacks, you may pay {E}{E}. If you do, put a +1/+1 counter on it.

Boseiju, Who Endures

{T}: Add {G}.
Channel — {1}{G}, Discard Boseiju, Who Endures: Destroy target artifact, enchantment, or nonbasic land an opponent controls. That player may search their library for a land card with a basic land type, put it onto the battlefield, then shuffle. This ability costs {1} less to activate for each legendary creature you control.

Acorn Catapult

{1}, {T}: Acorn Catapult deals 1 damage to any target. That permanent's controller or that player creates a 1/1 green Squirrel creature token.

Anvilwrought Raptor

Flying
First strike (This creature deals combat damage before creatures without first strike.)

Anara, Wolvid Familiar

As long as it's your turn, commanders you control have indestructible. (Effects that say "destroy" don't destroy them. A creature with indestructible can't be destroyed by damage.)
Partner (You can have two commanders if both have partner.)

Earl of Squirrel

Squirrellink (Damage dealt by this creature also causes you to create that many 1/1 green Squirrel creature tokens.)
Creature tokens you control are Squirrels in addition to their other creature types.
Other Squirrels you control get +1/+1.

Garruk, Cursed Huntsman

0: Create two 2/2 black and green Wolf creature tokens with "When this creature dies, put a loyalty counter on each Garruk you control."
−3: Destroy target creature. Draw a card.
−6: You get an emblem with "Creatures you control get +3/+3 and have trample."

Forest

Phoenix Chick

Flying, haste
Phoenix Chick can't block.
Whenever you attack with three or more creatures, you may pay {R}{R}. If you do, return Phoenix Chick from your graveyard to the battlefield tapped and attacking with a +1/+1 counter on it.

Squirrel Sanctuary

When Squirrel Sanctuary enters the battlefield, create a 1/1 green Squirrel creature token.
Whenever a nontoken creature you control dies, you may pay {1}. If you do, return Squirrel Sanctuary to its owner's hand.

Basking Rootwalla

{1}{G}: Basking Rootwalla gets +2/+2 until end of turn. Activate only once each turn.
Madness {0} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Gilded Goose

Flying
When Gilded Goose enters the battlefield, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
{1}{G}, {T}: Create a Food token.
{T}, Sacrifice a Food: Add one mana of any color.

Liege of the Hollows

When Liege of the Hollows dies, each player may pay any amount of mana. Then each player creates a number of 1/1 green Squirrel creature tokens equal to the amount of mana they paid this way.

Artificer's Assistant

Flying
Whenever you cast a historic spell, scry 1. (Artifacts, legendaries, and Sagas are historic. To scry 1, look at the top card of your library, then you may put that card on the bottom of your library.)

Triumph of the Hordes

Until end of turn, creatures you control get +1/+1 and gain trample and infect. (Creatures with infect deal damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Spore Frog

Sacrifice Spore Frog: Prevent all combat damage that would be dealt this turn.

Mirari's Wake

Creatures you control get +1/+1.
Whenever you tap a land for mana, add one mana of any type that land produced.

Nut Collector

At the beginning of your upkeep, you may create a 1/1 green Squirrel creature token.
Threshold — Squirrel creatures get +2/+2 as long as seven or more cards are in your graveyard.

Squirrel Nest

Enchant land
Enchanted land has "{T}: Create a 1/1 green Squirrel creature token."

Krosan Beast

Threshold — Krosan Beast gets +7/+7 as long as seven or more cards are in your graveyard.

Ravenous Squirrel

Whenever you sacrifice an artifact or creature, put a +1/+1 counter on Ravenous Squirrel.
{1}{B}{G}, Sacrifice an artifact or creature: You gain 1 life and draw a card.

Arcane Flight

Enchant creature
Enchanted creature gets +1/+1 and has flying.

Toski, Bearer of Secrets

This spell can't be countered.
Indestructible
Toski, Bearer of Secrets attacks each combat if able.
Whenever a creature you control deals combat damage to a player, draw a card.

Chatter of the Squirrel

Create a 1/1 green Squirrel creature token.
Flashback {1}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Shinewend

Flying
Shinewend enters the battlefield with a +1/+1 counter on it.
{1}{W}, Remove a +1/+1 counter from Shinewend: Destroy target enchantment.

Blink Dog

Double strike
Teleport — {3}{W}: Blink Dog phases out. (Treat it and anything attached to it as though they don't exist until your next turn.)

Might of Oaks

Target creature gets +7/+7 until end of turn.

Mad Dog

At the beginning of your end step, if Mad Dog didn't attack or come under your control this turn, sacrifice it.

Silverchase Fox

{1}{W}, Sacrifice Silverchase Fox: Exile target enchantment.

Sol Ring

Ferocious Pup

When Ferocious Pup enters the battlefield, create a 2/2 green Wolf creature token.

Mushroom Watchdogs

Sacrifice a Food: Put a +1/+1 counter on Mushroom Watchdogs. It gains vigilance until end of turn. Activate only as a sorcery.

Zodiac Dog

Mountainwalk (This creature can't be blocked as long as defending player controls a Mountain.)

Thieving Otter

Whenever Thieving Otter deals damage to an opponent, draw a card.

Harmless Offering

Target opponent gains control of target permanent you control.

Canyon Jerboa

Landfall — Whenever a land enters the battlefield under your control, creatures you control get +1/+1 until end of turn.

So Shiny

Enchant creature
When So Shiny enters the battlefield, if you control a token, tap enchanted creature, then scry 2.
Enchanted creature doesn't untap during its controller's untap step.

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.)

Diminish

Target creature has base power and toughness 1/1 until end of turn.

Bear Cub

Selfless Savior

Sacrifice Selfless Savior: Another target creature you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Acorn Harvest

Create two 1/1 green Squirrel creature tokens.
Flashback—{1}{G}, Pay 3 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Tenacious Pup

When Tenacious Pup enters the battlefield, you gain 1 life. You get a one-time boon with "When you cast a creature spell, that creature enters the battlefield with an additional +1/+1 counter, trample counter, and vigilance counter on it."

Golden Hind

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.

Mirkwood Bats

Flying
Whenever you create or sacrifice a token, each opponent loses 1 life.

Rampant Growth

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

Catlike Curiosity

Enchant creature
Enchanted creature has "Whenever this creature deals combat damage to a player, draw a card."
If Catlike Curiosity would be put into a graveyard from anywhere, exile it instead.

Mischievous Catgeist

Whenever Mischievous Catgeist deals combat damage to a player, draw a card.
Disturb {2}{U} (You may cast this card from your graveyard transformed for its disturb cost.)

Mischievous Catgeist // Catlike Curiosity

Howl of the Night Pack

Create a 2/2 green Wolf creature token for each Forest you control.

Beastmaster Ascension

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