Cornelius and Mr. Chitters

Whenever a nontoken scarecrow enters, each player creates a 1/1 green Squirrel token.

At the beginning of your combat phase, choose Squirrels or Scarecrows;
If you choose Squirrels, sacrifice all squirrels you control. Scarecrows get +X/+X where X is the number of squirrels sacrificed this way.

If you choose Scarecrows, sacrifice all scarecrows you control. Squirrels get +X/+X where X is the number of scarecrows sacrificed this way.