They're more like equipment.
Let's just leave the familar/cohort/mount/bff options up to the DM.
Updated.
Here's the next one...
Drop Spider (Huge variety)
CLIMATE/TERRAIN: Any non-arctic
FREQUENCY: Rare
ORGANIZATION: Platoon (pack)
ACTIVITY CYCLE: Any
DIET: Carnivore
INTELLIGENCE: Low (5-7)
TREASURE: Nil
ALIGNMENT: Chaotic evil
NO. APPEARING: 2-10
ARMOR CLASS: 6
MOVEMENT: 18, Wb 12
HIT DICE: 2+2
THAC0: 19
NO. OF ATTACKS: 1
DAMAGE/ATTACK: 1-6
SPECIAL ATTACKS: Poison, webs
SPECIAL DEFENSES: Nil
MAGIC RESISTANCE: Nil
SIZE: M (5’ diameter)
MORALE: Elite (14)
XP VALUE: 420
Drop spiders are web-spinning huge spiders specially trained to launch themselves off the deck and lower themselves via web strands onto ships, groundlings, or anything else passing beneath the windship. Even if a drop spider’s web strand is severed unexpectedly, the spider can often (80%) react quickly enough to shoot another strand, reaffixing itself to the Xakhun vessel before the end of the same round, so long as it remains within 30 feet of the windship. Moreover, the spider can withstand falls of any distance due to a unique cartilage structure in its legs. Thus, a drop spider could fall hundreds of feet and land on the ground without injury. However, for every 100 feet fallen, the drop spider must spend one round “stabilizing” itself. During this period of recovery, the spider cannot attack and suffers a -4 penalty to Armor Class.
Drop spiders have a thin mesh between their legs that enables them to glide toward designated targets with greater accuracy. They do not plummet uncontrollably, instead spiraling downward, seeking the best place to land and attack.
Drop spiders bite their prey, injecting Type D poison. In creating these beasts, the Xakhun also tampered with the venom. Not only does the affected victim suffer damage, but the poison causes severe disorientation. Anyone failing a save vs. poison succumbs to this “residual effect” immediately, suffering a -2 penalty to attack rolls and saving throws. This effect is not cumulative with multiple bites.
Drop spiders can shoot their webs either to secure a line to climb (or descend) or to entangle a foe. In the latter case, treat the drop spider’s web as that of a large spider, except that the drop spider’s web is a single strand with a range of 30 feet.