The Rathtar is a ravenous predator that inhabits sub-tropical arid regions of Sppang, usually in places never settled by humanoids. Its body is a sphere of muscle 90cm across—this stretches when it consumes something. The "front" third of the body is dominated by an expanding maw; the "bottom" third has a tough underbelly (treat as AC 3); much of the rest of the sphere features numerous simple yellow eyes about the size of a man's hand. Eight strong tentacle-like limbs allow the creature to pull itself along and to swing from overhanging holds. Below the mouth are two true tentacles with powerful grasping structures.
The Rathtar moves by rolling itself along the ground. They easily use overhead structures to swing along off the ground, use vertical structures to haul themselves up/over those structures, and are completely unphased by rough terrain. Rathtar are good swimmers, though they tire after thirty minutes in the water and will drown if left in water indefinitely.
These nightmare creatures capacity for eating, and can swallow three Medium-sized humanoids in succession. They strike by grabbing prey with the tentacles and stuffing it into the rathtar's vicious mouth—which consists of rings of teeth surrounding a telescoping esophagus. The teeth do 4d8 damage per turn, but a rathtar will swallow things before they're entirely dead because the esophagus contains plenty more teeth. If the rathtar has eaten its fill, at least one Medium-sized prey—surviving or dead—will carried off for later consumption, which usually occurs within an hour. A sated rathtar will sleep for days, and will have difficulty rousing. A rathtar that has engaged in combat must similarly rest for up to six hours.
Rathtar are immune to charm spells, as well as magic missile and lightning, but take normal damage from most weaponry and double damage from cold-based attacks. Its limbs have an AC of 7, but move at such speed to have an effective AC similar to the body.
Rathtar eyesight is very limited, meaning they cannot discern transparent materials or impediments such as cages. They appear to hunt through smell and sensing vibrations, and hunt by grabbing anything smaller than its mouth. A rathtar will swallow anything not obviously poisonous, burning, or in the process of detonating.
Rathtar have been known to attack until dead, accepting terrible wounds in their effort to eat. Rathtar cannot be trained, period.
Rathtar teeth are worth 25gp each; an individual creature has about sixty of them in saleable condition.