Nut Collector

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

Squirrel Mob

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

Overrun

Creatures you control get +3/+3 and gain trample until end of turn. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)

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.

Llanowar Elves

Greenweaver Druid

Harmonize

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.)

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.)

Prized Unicorn

All creatures able to block Prized Unicorn do so.

Chorus of Might

Until end of turn, target creature gets +1/+1 for each creature you control and gains trample.

Traproot Kami

Defender; reach (This creature can block creatures with flying.)
Traproot Kami's toughness is equal to the number of Forests on the battlefield.

Garruk Wildspeaker

+1: Untap two target lands.
−1: Create a 3/3 green Beast creature token.
−4: Creatures you control get +3/+3 and gain trample until end of turn.

Squirrel Nest

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

Biorhythm

Each player's life total becomes the number of creatures they control.

Naturalize

Arbor Elf

Primal Frenzy

Enchant creature
Enchanted creature has trample.

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.

Sylvan Ranger

When Sylvan Ranger enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Blunt the Assault

You gain 1 life for each creature on the battlefield. Prevent all combat damage that would be dealt this turn.

Craterhoof Behemoth

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

Coat of Arms

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

Parallel Lives

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.