The Skeksis engineered these massive creatures to serve as their guardians and soldiers, thus protecting their castle while also waging a campaign of extinction against Gelflings. The Garthim appear to be a mixture of beetle and crab anatomies, though closer inspection reveals them as bipeds with supporting tentacle-like appendages. One arm terminates in a vicious crab pincher, while the other boasts a fingered claw for snatching up prisoners.
Diet of the Garthim
In "A Natural History of The Dark Crystal: The Conceptual Design of Brian Froud," Catriona McAra points out that the Garthum may actually exist as a thought-projection of the Skeksis. After all, we see them vanish into thin air -- minus their shells -- when the Skeksis finally lose power. This would certainly simply their anatomies somewhat as their massive weaponry would require tremendous energy. As biologist Douglas J. Emlen points out in "Animal Weapons: The Evolution of Battle," muscles are expensive to maintain even when resting, and males with big claws require the most muscle -- and he's just talking about natural-world fiddler crabs there.
Indeed, some form of supernatural sustenance might well be required, especially since we never see the Garthim feed. They venture out into the wilds only to ravage Podling villages and drag back live captives. Do they munch down on a specialized food supply back at the Skeksis' castle? Or do they graze wild flora during their conquests, making them comparable to parasitoid wasps who bring live spiders back to their nest for the larvae yet depend exclusively on nectar as adults?
Garthim Defense Spending
But again, these are artificial creatures that serve an unnatural agenda. They don't live to eat and breed, but rather to do their masters' dark bidding. The Garthim are a weapons race, and like most human weapons they're incredibly expensive.
Just compare the Garthim to the U.S. Air Force B-2 stealth bomber, built at a reported cost of $2.1 billion per plane and requiring 50 to 60 hours of ground maintenance for every one hour in the air [source: L.A. Times]. That's not even taking into account upgrade efforts. Contractors Northrop Grumman currently holds a $9.9 billion contract to complete maintenance and modernization on the 20-plane fleet [source: DoD Buzz]. I'd put that on par with powering an army of giant beetles to kidnap potato farmers.
As Emlen points out, human weapons of war have always been extraordinarily expensive and available only to the exceedingly rich. Even the medieval knight, easily dismissed as a mere soldier-on-a-horse, entailed a whole grocery list of specialized equipment and maintenance teams, on top of the individual knight's training and labor-free life of wealth and privilege.
Weapons are expensive, whether they serve mate selection, warfare or genocidal fervor. Yet there's a tipping point for all three cases, where the cost of the weapon exceeds the benefits of its existence.
The Garthim nearly succeeded in wiping out the one species prophesied to end the Skeksis' rule, but the two individuals left alive proved enough. Despite their extravagance and war-mongering ways, the Skeksis didn't spend quite enough on their defense.
Monster of the Week is a - you guessed it - regular look at the denizens is of our monster-haunted world. Sometimes we'll focus on the cultural aspects, but mostly we'll look at the possible science behind a creature of myth, movie or legend. Be sure to explore the Monster Gallery as well as the Monster Science video series.