The ahool is a flying cryptid that is either a huge bat or a living pterosaur or flying ape, according to certain tales. Science has never seen such a monster, and there is no objective proof that it exists as stated.

It is not well documented, and there is little credible information – and in this case, no material evidence – about it, as with many cryptids. It is supposed to reside in the deepest jungles of Java, and is named for its unique cry, A-hool (some sources translate it as ahOOOOOooool).

It has a monkey/ape-like head with huge black eyes, massive claws on its forearms (roughly the size of a baby), and a body coated in grey fur, according to the description. The fact that it has a 3 m wingspan is maybe the most interesting and amazing characteristic (10 ft).

This is about twice the length of the world’s biggest (known) bat, the common flying fox. Dr. Ernest Bartels originally characterised it when studying the Salak Mountains on the island of Java, according to Loren Coleman and Jerome Clark. Cryptozoologist Ivan T. Sanderson hypothesised that it may be a relative of Kongamato in Africa.

Others have speculated that it might be a living fossil pterosaur, based on its leathery wings. As far as we know, most pterosaurs possessed downy fluff on their wings to minimise heat loss; this may or may not have been essential in a tropical climate, depending on the metabolism of these creatures. On the other hand, there may be a completely uninteresting explanation:

The Javan Wood-owl (Strix (leptogrammica) bartelsi) and the Spotted Wood-owl (Strix seloputo) are two big earless owls that live on the island of Java. They will be between the Spotted Owl of North America and the Tawny Owl of Eurasia in size and the eagle owl (horned owl) in size, measuring 40-50 cm (16-20 in) in length and 1.20 metres in wingspan (4 ft).

Despite this difference, the wingspans of flying animals not held in hand are sometimes exaggerated (see also Thunderbird), particularly by scared spectators.

Regardless of size, the Javan or Bartels’s Wood-owl appears to be a particularly promising candidate for solving the ahool mystery: it has a prominent flat “face” with large dark eyes exaggerated by black rings of feathers and a beak that protrudes only slightly, and it appears greyish-brown from below.

Its cry is distinct, consisting of a single, intermittent scream that sounds like HOOOH!. It is very territorial during the breeding season, as are most big owls, and will frighten visitors away with fake assaults from above and behind.

Because an owl’s flight is almost quiet, the victim of such sweeps generally notices the owl when it is growling and holding outstretched talons (held at “breast” height to the spectator) and has just enough time to dart away.

The Javan Wood-owl is a very uncommon and secretive bird that hides during the day and is seldom seen even by ornithologists. It lives in isolated montane forests at an altitude of 1000-1500 metres, and it does not accept human invasion, logging, or other disturbances well.

Despite the cryptid’s look and behaviour giving the impression of a mammal, the Javan Wood-owl matches the traits of the ahool remarkably well. The apparent differences might be attributable to observer error caused by the conditions of being dive-bombed in a lonely, gloomy woodland by a ferocious growling and clawing bird.

Despite this, the Java wood-owls are rarely addressed in cryptozoological discussions on the ahool, and most cryptozoological authors appear to be completely oblivious to the birds’ existence.

Regardless, it is unclear how widely the owls are recognised among residents, particularly the local names – if any – and whether they are prevalent in areas where ahool tales are common. It’s also conceivable that the cry and the flying animal aren’t the same thing; even the locals aren’t always sure which forest species produces either sound.