Ambigolimax parvipenis is a species of air-breathing land slug, a terrestrial pulmonate gastropod mollusc in the Limacidae.

[3][4] This work showed it to be distinct from the externally similar Ambigolimax valentianus on the basis both of genital anatomy and of the genetic sequences in the barcoding COI mitochondrial gene.

[4] Like other limacids, they are slim with a pointed tail, and the pneumostome lies in the posterior half of the mantle.

The background colour is yellowish-grey to various shades of brown, with the flanks paler and the sole pale cream.

[1][4][7] The penis is distinctive by its small size (roughly half the length of the bursa copulatrix and duct) and lack of a penial appendage (although vestigial knobs are occasionally present).