Thick shelled, but margin of outer lip not reinforced; very variable in height of spire and in proportional width; sculpture of dense axial threads interrupted by slight spiral grooves, which do not form distinct granules but give the intervals between the threads the appearance of axially aligned series of short slash-like grooves; protoconch smooth. Ground colour off-white, buff or pale brown, usually with dark brown axial stripes, which are more or less straight (instead of wavy as in most striped achatinids), occasionally coloured brown overall; both inner and outer lip deep pink. In KwaZulu-Natal attains a shell length of about 1 50 mm.
A tropical East African species whose range extends south to the Limpopo Province, Gauteng and Mpumalanga, and down the coastal region of KwaZulu-Natal at least to the Ramsgate area, and inland to Pietermaritzburg and theThukela Valley near Kranskop. It inhabits leaf-litter and underbrush in coastal lowland and dune forest, and suburban gardens, but also occurs in drier habitats such as valley thicket and savanna woodland; common. Egg clutches may contain as few as 20 eggs or as many as 1 20. It is possibly the only South African achatinid with the potential to become a pest, and in fact it has been implicated in reports of damage to citrus orchards in some countries to the north.
An important character that will distinguish even juveniles of A immaculate from other eastern South African agate snails (including the equally large Metachatina kraussi) is its smooth apex, which lacks the granules or wavy, rough axial threads that occur in other species.
Narrow specimens were once regarded as a distinct species, Achatina panthera Ferussac, 1832. In appearance, A. immaculata closely resembles the notorious giant African snail (Achatina fulica Bowdich, 1 822), which is not known to live further south than Mozambique (Angoche and the Bazaruto Archipelago). A. fulica tends to be narrower in proportions than A. immaculata and its aperture margin lacks the pink colour of that species.