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."

location approximate

Apparently introduced to Bioko Island, as cited in this APHIS report. Widespread, and common to see being sold for human consumption.