Hit Dice: 2
Armor Class: 9 
Attacks: 2 x Pincers (1d4)
Saving Throw: 16
Special: Fear, Flight, Greater Than Human Intelligence, Weapons Resistance (See Below)
Move: 4/10 (flying)
Challenge Level/XP: 6/240
These bizarre aliens resemble nothing less than pinkish, man-sized crustaceans with a convoluted, pulpy ovoid mass covered in short cilia and antenna answering for a head. Large membranous wings sprout from their back and they have several sets of insectile limbs protruding from its underbelly. Composed of matter beyond normal human understanding and possessing an anatomy that is more fungoid than animal, they are quite resilient to damage from physical attacks. Any non-magical weapon does the minimal amount (plus any Strength bonuses) possible. They are capable of communicating with humans through a buzzing parody of our speech.
Their main abode in our solar system is a distant, dark, dwarf planet called “Yuggoth” by some priests and arcane scholars, is only a small colony of a larger interstellar civilization. Eons earlier, the Spawn of Yuggoth came to Earth and built a great city around Mount Yaddith-Gho where they mined the volcano for rare elements. With them, they brought the Great Old One, Ghatanothoa , which they kept within their mountain colony for some unguessable purpose. After many millennia, the Spawn's colony became deserted; some believe they died out, others say it was abandoned.
While they can also be adept spellcasters, paying homage to Shub Niggurath and The Crawling Chaos when their uneartlhy designs require it, their scientific knowledge is vast. Artifacts from their reign are highly prized by scholars and sorcerers, particularly the magical lagh metal which only a few human artisans have learned to sculpt and smith into weapons or other devices.