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.)

Kindred Summons

Choose a creature type. Reveal cards from the top of your library until you reveal X creature cards of the chosen type, where X is the number of creatures you control of that type. Put those cards onto the battlefield, then shuffle the rest of the revealed cards into your library.

Squirrel Sovereign

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.

Haunted One

Commander creatures you own have "Whenever this creature becomes tapped, it and other creatures you control that share a creature type with it each get +2/+0 and gain undying until end of turn." (When a creature with undying dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Species Specialist

As Species Specialist enters the battlefield, choose a creature type.
Whenever a creature of the chosen type dies, you may draw a card.

Druid's Call

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

Underworld Hermit

When Underworld Hermit enters the battlefield, create a number of 1/1 green Squirrel creature tokens equal to your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Obelisk of Urd

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
As Obelisk of Urd enters the battlefield, choose a creature type.
Creatures you control of the chosen type get +2/+2.

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.

Graaz, Unstoppable Juggernaut

Juggernauts you control attack each combat if able.
Juggernauts you control can't be blocked by Walls.
Other creatures you control have base power and toughness 5/3 and are Juggernauts in addition to their other creature types.

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.

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.

Kindred Dominance

Choose a creature type. Destroy all creatures that aren't of the chosen type.

Altar of the Brood

Whenever another permanent enters the battlefield under your control, each opponent mills a card.

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.

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.

Squirrel Nest

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

Squirrel Mob

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

Pyre of Heroes

{2}, {T}, Sacrifice a creature: Search your library for a creature card that shares a creature type with the sacrificed creature and has mana value equal to 1 plus that creature's mana value. Put that card onto the battlefield, then shuffle. Activate only as a sorcery.

Cloakwood Hermit

Commander creatures you own have "At the beginning of your end step, if a creature card was put into your graveyard from anywhere this turn, create two tapped 1/1 green Squirrel creature tokens."