While 'carnivorous' and 'snail' are two words that most people wouldn't expect to find next to one another, these slow moving predators are actually quite common in some regions of the wet-tropics.
This is one of our local carnivorous snails, Strangesta sp. (Rhytididae). Here is a series of photos showing it attacking and consuming a young Hadra webbi. Strangesta spp. have an extendible mouth part known as the buccal mass. It is a long, cylindrical muscular organ - the white tissue visible in the last image. This is extended inside the shell of the prey to enable the radular to access the soft tissue.