This race of strange mollusk creatures dwells in abundance in a city beneath the Earth, demonstrating a culture of commerce and a special fondness (bordering on addiction) for junk food from the surface world. It is unclear if the Langastoids are Inhumanoids, Mutores, or some other breed of lifeform. Earth Corps first discovers their crude civilization during events surrounding the inversion of Earth's magnetic field, when they are captured by Langastoid guards and put up for sale on the city auction block along with their gear, eventually making a getaway on bizarre slug-like steeds with help from Tank. In their next subterranean encounter, Earth Corps was greeted more peacefully by Langastoid farmers claiming to need help against attacks on their city by Tendril, but this proves to be a deception orchestrated by the Inhumanoids, who have bribed their Langastoid lackeys with the promise of surface food. During Metlar's final stand, Tendril relies on the same fattening ploy to buy the Langastoids' allegiance in battle, but they are quickly distracted by a payload of junk food strategically dumped to occupy their attention while Earth Corps takes the fight to Metlar's doorstep.