Coming courtesy of the undisputed kings of cryptids and cassettes, the Ahool is a product of Indonesia, manufactured in its forests by hardworking explorers. So-named for their apparent cry, there's not much info on these things that I can reliably find. I might just not be looking hard enough.
Mechanically, the ahool is a pretty terrifying grappler, with the ability to cause dexterity damage to whatever unfortunate soul is trapped in its grasp. As for flavor, there's not a whole lot... which only gives us more to work with.
The Langford Grain & Sugar Company has lost some of its surveyors in the Isle of Dutro, and while their representatives are foppish chauvinists, the pay is too good to pass up. As it turns out, they've already been eaten, and if the party can't collect their notes and leave by sundown, they might be next.
The intelligent orangutans of Dunpur City are beginning to disappear, coinciding with a sudden increase in ahool sightings. Oddly, these normally dark-furred ahool all seem to sport an orange coat...
When a doctor is carried off by an ahool in broad daylight, his widow tasks a group of sellswords to retrieve his body for burial, lest he rise as a pocong in cheap cheesecloth. When the party tracks him to the ruins of a burnt outpost, they find him alive and (mostly) well, along with the ahool who stole him and its ill and visibly pregnant mate.