Tandonia rustica is a species of air-breathing, keeled, land slug, a shell-less terrestrial gastropod mollusc in the family Milacidae.

It is whitish in colour creamy or reddish to yellowish grey with numerous black dots.

,The vas deferens opens symmetrically, the spermatheca is elongate with a sharp pointed end, its duct slightly shorter and with a swelling half-way.

(Francisco Welter Schultes) This slug is native to Central Europe (Austria, Czech Republic, France, Germany, Italy, Liechtenstein, Luxembourg, Poland, Romania, Slovenia, and Switzerland); it has spread/been introduced much wider (Belgium, Croatia, Corsica, Great Britain, Hungary, Ireland, Slovakia, and the Netherlands[2]).

[3] Deciduous and mixed forests on mountain slopes with limestone rock rubble, also in open habitats on calcareous soils.