Thresher Maw (Mass Effect)

Thresher Maw

from Mass Effect universe

Thresher Maws are subterranean carnivores that spend their entire lives eating or searching for something to eat. They are enormous, violent creatures that burst up from the ground without warning when disturbed.

They reproduce via spores that lie dormant for millennia, yet are robust enough to survive prolonged periods in deep space and atmospheric re-entry. As a result, thresher maw spores appear on many worlds, spread by previous generations of space travelers. 

Thresher maws are solitary creatures; two or three at most can be found on a single planet. They live alone in nests spanning large areas underground. They can grow to be in excess of 30 metres tall above the ground, with a body nearly twice that size beneath the surface. The body of an adult thresher maw never entirely leaves the ground; only the head and tentacles erupt from the earth to attack.

Aggressive and highly territorial, thresher maws feed by absorbing huge amounts of solar radiation and survive best on planets, asteroids or moons with little or no atmosphere. They also consume minerals and ores from the ground itself and use an odd form of photosynthesis to combine solar radiation and minerals into energy they can use to fuel their significant mass.

Due to their size, and their burrowing style of movement, thresher maws are immobile above ground, but can move incredibly quickly below. They can take a lot of damage and can be very hard to kill. Their attacks consist of spitting powerful viscous acid that splashes on contact, burrowing up from beneath their prey, and smashing with their claws in close range while emitting infrasound. Due to the nature of their attacks, they completely ignore shields. (source)