[9] Because of the slug's white colour and nocturnal habits, and because it is so rarely seen, it was given the species name ysbryda, the word "ysbryd" meaning ghost in the Welsh language.

Bill Symondson speculated that the slug originally evolved in cave systems alien to the UK, and may possibly have arrived in Wales in soil in a potted plant.

[4] The first specimen was collected in the churchyard of Brecon cathedral on 29 December 2004, but its significance was overlooked at the time.

[5] The slug is not harmful to humans, but as a presumed introduced species, more records from Britain are being solicited, partly on the basis of an appeal to the public.

Two specimens of what is probably the same species (they were immature, so difficult to identify) have been recognised from two sites in the Crimean mountains in Ukraine.

[15][3] The specific epithet ysbryda, is derived from Welsh ysbryd, meaning a ghost or spirit.

The name alludes to the species' ghostly appearance, nocturnal, predatory behaviour and the element of mystery surrounding its origin.