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.

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.)

Sylvan Anthem

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

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.

Squirrel Mob

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

Nested Shambler

When Nested Shambler dies, create X tapped 1/1 green Squirrel creature tokens, where X is Nested Shambler's power.

Squirrel Sovereign

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.)