This is not a slug. It is a snail. A giant, carnivorous, cannibalistic snail that hunted its own kind through the leaf litter of ancient Northland forests. But early Europeans – confronted with a large, slimy, shelled creature that moved like molasses – sometimes called it a slug out of ignorance. The name stuck in some circles. So here we are: the giant New Zealand slug that was not a slug, is now extinct, and left behind only its shell as a witness. Size and appetite made it special. The living kauri snail is already a remarkable creature – a handsome, striped shell about the size of a plum, with a body that stretches to the length of your thumb. It is a predator. It hunts other snails, following their slime trails, tracking them like a leopard through the grass. When it catches one, it wraps its body around the victim, pins it down, and rasps a hole through the shell with its radula – a toothy, tongue-like organ. Then it eats the occupant alive. Slowly. Now imagine that snail bigger. A shell the size of your fist. A body that stretches to the length of a banana. A predator that could take on larger prey – giant earthworms, large slugs, even small wētā. That was the giant Paryphanta, and it was the tiger of the leaf litter. It crawled. Slowly. Relentlessly. A snail's life is measured in centimetres per minute, but it gets where it needs to go eventually. It laid eggs – small, leathery, pearl-like capsules – in the damp soil under rotting logs. It lived for years, perhaps a decade or more, growing slowly, adding whorl after whorl to its shell. It was a creature of patience and appetite, and for millions of years, that was enough. Rats and deforestation destroyed it. The kiore (Pacific rat) arrived with Polynesian settlers. Rats love snails. A snail is a protein packet wrapped in a calcium shell – easy to carry, easy to crack, easy to eat. The giant Paryphanta, being larger and slower than its smaller cousin, would have been a prize target. Rats also eat snail eggs – the leathery capsules, buried in the soil, no defence at all. At the same time, Northland's kauri forests were cleared for gardens and settlement. The giant snail needed deep, damp, undisturbed forest with rotting logs and thick leaf litter. Take away the logs, the litter, the damp – take away the snail. The smaller kauri snail survived. It retreated into the remaining fragments of forest, grew smaller, grew shyer, grew less visible. But the giant form is extinct. A few shells in a cave, a few fragments in a midden, and the memory of a predator that used to hunt through the dark. The forest crawler is a name for something you will never see. A fist-sized shell, striped in amber and brown, moving slowly across a bed of moss, hunting its own kind. It used to crawl here. It does not crawl now.