Goblin Herbivore

Goblin Herbivore's power and toughness are equal to the number of lands in all graveyards.
Suspend X: {x}{3}{r}. {x} can't be 0. (Rather than cast Goblin Herbivore from your hand, exile it instead, and place {x} time counters on it, where {x} is the number of mana spent this way.)
Remove a time counter each upkeep. Whenever a time counter is removed from Goblin Herbivore, destroy target land.
When the last time counter is removed, cast Goblin Herbivore without paying its
mana cost.