Prophysaon andersoni, common name the reticulate taildropper, is a species of air-breathing land slug, a terrestrial pulmonate gastropod mollusk in the family Arionidae, the roundback slugs.
These slugs are notable for being able to self-amputate (autotomy) a portion of their tail.[1] [2]
Adults of this slug species are about 50 mm when active, but can exceed 60 mm in length. The color of the body is a grayish or reddish brown, or can be yellowish. The dorsum is furrowed with a reticulated pattern like a mesh of diamond shapes. The mantle of the slug has two dark lateral bands. The mucus is yellow or orange.[3]
This species of slug occurs in North America, including California, Oregon and part of Montana.