Littjara's Sage of Ancients

Changeling
When Littjara's Sage of Ancients enters the
battlefield choose a creature type. Littjara's Sage
of Ancients power and toughness are equal to the
number of creatures of the chosen type you
control.
{g}{g}: Lands you control become 0/1 shapeshifter
creatures with changeling until end of turn. Do
this only as a sorcery.