The icosapus is a rarely-seen skygoing invertebrate, much like a sea-going octopus, with twenty tenacles. Most reports place them within the Mists. They apparently prey upon empryean wolves and skysharks.
Natural philosophers claim that the older an icosapus gets, the larger it gets. There have been at least three reports of skyships entangled by the vast tentacles of ancient icosapuses, where the foul beasts fed upon much of the crew of the hapless skyship.
Travelers' Comments on Icosapuses
Once, I came across a skyship, the Endeavor, which had had an icosapus attack it, and the beast became entangled in the rigging. The crew were able to kill the creature easily after that. Lucky break, for if the icosapus had attacked the hull, it could have cracked it like an egg.
— Captain Froederik Wiki