Well, out here in Idaho we do have Gargantuan Slugs. These are about the size of an Aussie land train, carnivorous, spit a neurotoxin that causes you to turn orange and all your appendages to fall off, and leaves a slime trail that leaves the land sterile and barren for years after its passing. Here is a picture of some Idaho landscape devastated by the passage of these Slugs over a century ago -- as you can see, vegetation is only now returning and those who venture into the area (they are standing in the road in the picture) must wear protective clothing.

The voles here are slightly larger than a standard-issue mouse, but with a short tail. They eat the roots of grasses and other plants, causing damage to lawns and gardens.