Two rhumbats are generated in hidden rooms in the Kobold level.
In 1927, zoologist Ernst Bartels was in his home near the
Tjidjenkol River in Java when he heard a strange cry louder than
the other night sounds, a cry like "a-hool."
Bartels heard the sound twice more before the origin of the cries
moved off into the night. Bartels soon remembered a local legend
of the ahool or athol, a type of huge bat reputed to live in
Locals described the bat as the size of a small child, with
an 11-12 foot wingspan. The athol was supposedly covered in
grayish fur and had a face similar to that of a monkey or a man.
At times, it was seen sitting on the forest floor, with its wings
folded beside it; it was also reputed to have feet which pointed
backwards. During the day (like all bats, it was nocturnal), the
athol's refuge was supposedly a cave somewhere near a waterfall,
although at night it would fly over the river's surface in
search of fish.
[ "A Belfry of Crypto-bats." by Shuker, Dr. Karl P.N.
Fortean Studies 1, pp. 235-245. ]