small, brown, size of a quarter. In a very moist piece of dirt/soil.
location approximate
Bizarre encounter. I called it a "pancake slug" when I first saw it, the tentacles emerged from underneath its top surface.
From wiki: "The Veronicellidae, common name the leatherleaf slugs, are a terrestrial family of pulmonate slugs.... The dorsal surface of these slugs is entirely covered by the mantle or hyponota. These mollusks have a posterior located anus, eyes on contractile (not retractile) tentacles, and no lung or pulmonary organ. In these aspects they are anatomically distinct from most other types of terrestrial slugs, which typically belong to the order Stylommatophora, and which have a forward located anus, and retractile tentacles."
The Systellommatophora (synonym Gymnomorpha) is a clade of primitive, air-breathing snails and slugs according to the taxonomy of the Gastropoda (Bouchet & Rocroi, 2005). Some are marine and some are land-living, some have shells and some do not. They are distinguished by the location of the anus at the rear of the body.