The adult slug measures 10-20 cm (4-8 in) in length and is generally a light greyish or grey-brown with darker spots and blotches, although the coloration and exact patterning of the body of this slug species is quite variable.
This species has a very unusual and distinctive mating method, where the pair of slugs use a thick thread of mucus to hang suspended in the air from a tree branch or other structure.
The body color is pale-grey, ash-colored, brownish or sometimes yellowish-white. The sole of the foot is a uniform ash or yellowish-ash color.
Elimia virginica belongs to the family Pleuroceridae, a group of snails that have thick, elongated shells.
The operculum in this species is proteinaceous, corneous, and paucispiral and is withdrawn when the snail is active.
However, this species, although introduced to the Lake Ontario drainage, has been largely out-competed by another introduced snail, this one from the Palaearctic ecozone, Bithynia tentaculata.
Thus Elimia virginica is now virtually absent from the Oswego drainage, and is possibly very reduced in abundance in other localities where it was introduced, due to such interspecific competition.