the drow city of Erelhei-Cinlu, due to the presence of a well-known mind flayer research center. Greyspace Illithids also have a strong presence in Greyspace and spheres beyond. The primary spelljamming ship used by illithids is the nautiloid, a 35-ton craft resembling a nautilus. Nautiloids are 125' to 180' long, including the tentacle-like piercing ram. The ship's coiled shell provides the comfort of enclosed space and protects the illithids from the rays of solar bodies. Less common illithid vessels such as the 25-ton squid ship, the 70-ton octopus, and the 100-ton cuttle command also resemble the cephalopods after which they are named. In Greyspace, the largest illithid settlements are the city of Sharpbeak on Celene and the settlement of Skullbringer in the Grinder. Worlds ruled by illithids in other spheres include Falx, Ssirik Akuar, Penumbra, and Glyth. In Ravenloft Illithids are the rulers of a domain in the Ravenloft campaign setting called Bluetspur, where their God-Brain is the darklord. In the 5th Edition campaign guide Van Richten's Guide to Ravenloft, it is revealed that an elder-brain became diseased by discovering a "malignant truth" and it began to prey "upon its peers [...]. Horrified by an affliction that infected only them, the other elder brains united and psionically expelled the diseased brain from existence. Or so they thought. From a place without time or reality, the Dark Powers plucked the dying elder brain and planted it upon a tormented world". Polygon highlighted that Bluetspur is "a world of cosmic horror populated by malevolent mind flayers that will make your heroes question their own memories". In Spelljammer According to Ken Rolston, the beholder and the mind flayer "win starring roles as intergalactic menaces" in Spelljammer, describing the mind flayers as "evil, brain-sucking horrors who have polished up their social skills sufficiently to present a dubiously neutral facade to trading partners as they secretly scheme toward the day when all intelligent races will be their vassals and brain-food". Mind Flayers are one of the primary factions in the Spelljammer campaign setting. While less prominent than the neogi, illithids are in complete control of Glyth, a Realmspace planet, and have been for millennia. They are also one of the two most powerful factions in The Astromundi Cluster setting. Illithids' primary ship type is the nautiloid, a 35-ton craft resembling a nautilus. Nautiloids are 125', or 180' long including the tentacle-like piercing ram. The ships'