Living underground and mostly out of sight, squiggly earthworms seem like such humble, mundane organisms -- that is, unless it's Australia's Giant Gippsland earthworm, which is believed to be the world's largest species of worm.

Native to southeastern state of Victoria, and found only in the Bass River Valley of South Gippsland, the Giant Gippsland worm (Megascolides australis) measures on average 3.3 feet (1 metre) long, and 0.79 inches (2 centimeters) in diameter, and weighs about 0.44 lb (200 grams). However, these long-lived invertebrates can survive up to 5 years or more, maturing to a whopping 9.8 feet (3 meters) in length.

The Giant Gippsland worm thrives best in clayey, wet subsoils of river banks, burrowing deep to create their networked habitats. Unlike their smaller cousins which come to the surface to defecate, the Giant Gippsland worm deposits its castings underground, relying on heavy rains to flush out the waste from its burrows.

Highly sensitive to aboveground vibrations, the Giant Gippsland responds to unknown intruders' footsteps by moving away, producing audible squelching noises that can be clearly heard on the surface.

The Giant Gippsland worm is currently classified as a protected species, its numbers having been reduced by the introduction of agriculture into this region of Australia. Other limiting factors include its low rate of reproduction and slow development -- the giant worm produces one large egg capsule of 4 to 7 centimeters (2.75 inches) in length, which takes one year to incubate into a single offspring.

In honour of this remarkable and rare earthworm, locals in the town of Korumburra hold an annual worm festival with parades, games and the crowning of an earthworm Queen. Forget those overblown sci-fi sandworms; these giants are the real deal on Earth.