Stone Calendar (Fall)

If it is September, all forests produce {g} instead
of {g}.
If it is October, all black creatures have "When
this creature deals combat damage to a player,
that player must either give its controller a card
from their hand (change of ownership is
permanent) or this creature gains doublestrike."
If it is November, all creatures have +1/+1 for
each other creature its controller controls.