Commonly seen crossing the trail on damp days, these slugs can grow up to 10 inches long. They're the second largest species of terrestrial slug. Often bright yellow, they may also be greenish, brown, tan, or white, and may have black spots.

Being a slug, they are of course deeply weird. They move using their stomach, which doubles as a foot: apparently not a race-winning technique as their speed tops out around 6 inches per minute. A row of microscopic teeth is positioned on the ground at the front of the stomach. They secrete a numbing mucus to keep themselves moist and deter predators.