Serena, Goddess of the Sea

Serena can't attack or block.
As long as your devotion to green is less than
seven, Serena, Goddes of the Sea has Protection
from Everything (Each {g} in the mana costs of permanents you control counts towards your
devotion to green.)
Whenever a land enters the battlefield under
your control, you may tap it. If you do, search
your library for a land card and put it onto the battlefield.