Liege of Osiris

Flying
As long as Liege of Osiris isn't attacking, its
power and toughness are each equal to the
number of Forests you control. As long as
Liege of Osiris is attacking, its power and
toughness are each equal to the number of
Forests defending player controls.
{t}: Target land becomes a Forest until Liege
of Osiris leaves the battlefield.