If you visit the magnificent myrtle beech (Nothofagus cunninghamii) and Blackwood (Acacia melanoxylon) forests of SW Victoria at this time of year, might be lucky enough to spot one of these snails. They are often found crawling across the tracks at (Mait's Rest and Melba Gully. (The snails are crawling, that is. Although you might try looking for them while you're on your hands and knees.)
The Otway Black Snail belongs to the Rhytididae, a family of carnivorous snails with a Gondwanan origin.
Rhytidids feed on worms and other snails. They snare prey on their sharp teeth and drag it back into the mouth. It's not quite Alien but it's pretty gruesome on a small (and slow) scale.
Other species of Victaphanta live in closed forests of the Dandenong Ranges and in Tasmania. In Australia, rhytidids are found in the forests and dense scrub along most of the coast. Elsewhere they occur in South Africa and New Zealand, where they grow to a huge size. (And eat whatever they like.)
[Thanks, once again, to MM for the great photograph of the OBS]