Slow Expansion

Destroy target land. If {p/b} was used to cast the
spell then all non-mutant creatures get a
-1/-1 counter. If 2 life was paid to cast this, exile
all permanents that enter the graveyard this way.
"Slow expansion is quite an understatement, the
Visitor's virus is, spreading at a rate of 6000 acres
a day" - Dr. Ozo, the next gen.