The creature know as the “krajen” is a otherworldly giant space squid. It develops in three stages: small spaceborne spores, a barnaclelike immature stage, and the huge, adult krajen that is the bane of the Spelljammer shipways. In its adult stage, the krajen can grow to be 40 feet long. Its tubelike body is dominated at one end by a thick central tentacle, the base of which is surrounded by a cluster of smaller tentacles.
In their spore form they can be slain by such simple spells as cure disease. They drift like wind seeds in the Void, waiting for the approach of a ship or other solid body. They are so small that a Spelljamming ship can pass through a cloud of them without stopping and without its crew noticing. It is only when the spores take root in the hull of the ship that they are noticeable.
Krajen spores can take root in any solid object, including asteroids, ship hulls, and large living creatures. Once planted, the base of the spore widens and digs into the surfacer while the outer surface hardens into a shell similar to a barnacle’s. The central tentacle is nested in an opening at the top of this shell. In case of normal attacks on the immature krajen, the tentacle can whip out to attack enemies in the area, lashing out at random. When dormant, the tentacle is tucked inside the top of the shell.
Immature krajens can survive without air, and in fact prefer the stale air of bad air envelopes over the healthy air of areas replenished by green plants. They do need a solid surface to draw nutrients from, though each one can also absorb nutrients from dead bodies that it and the rest of the colony have destroyed.
If you travel the Void, fear the krajen!