Graboids are the main antagonist of the Tremors movie franchise. Bearing a superficial resemblance to gigantic worms or snakes, they dwell in hot, arid locations such the desert of the American southwest. Their eggs can lay dormant for up to 300 years, only hatching once exposed to a heat source. The hatchlings, although small, are carnivorous and will begin hunting soon after birth. Hatchlings hunt in packs, shooting up from the ground, grabbing their prey, and dragging it back underground, vibrating as a means to shift the soil. The creatures will reach full size in about 3 months; a mature graboid can measure 30 feet long and weigh 10-20 tons. Graboids hunt via sound, able to track something as small as a CD player across the surface.
Mature graboids have a slightly different hunting strategy. Once they have pinpointed the source of a noise, they burst from the ground and ensnare their prey with a trio of prehensile tentacles located within the beak. The tentacles themselves have toothed maws and a pair of horns; they can also reach up to 10 feet. Once ensnared, the prey is pulled underground and digested. Since they are so massive, fully grown graboids can no longer vibrate to move soil out of their way; instead they simply use spines along the body to move beneath the surface.
Graboids themselves are only one of three stages in the lifecycle of the creatures. Eventually, fully grown individuals will give birth to three Shriekers, dying in the process.
The African variety (dubbed "Inkanyamba" by local residents, after a legendary, lake-dwelling serpent from Zulu mythology) is longer and thinner than the North American variety, while also possessing detachable tentacles.