Dehl'nya, the Green

Immortal (Spells and abilities cannot
reduce this creature's toughness less than 1)
Landbond (You may pair this creature with an
unpaired land when either enters the battlefield. They
remain paired for as long as you control both of them.)
As long as Dehl'nya, the Green is paired with a
land, lands you control with the same name as
the paired land tap for an additional {g}.