I have had this idea knocking around in my brain as if something I read once and half-remember. It seems like a module or short adventure or something that I might have encountered at some point.
The adventure begins with travelling through a tunnel, cave, mine, or linear dungeon of some sort, with the usual sorts of encounters, and then lets out in a deep ravine with a swift river at the bottom of it. A path leads to a house of sorts carved or constructed out of the ravine wall, such that the only way out is to fly, ride the river, or return through the tunnel. In this dwelling, which is elaborate and luxurious, live several children, apparently normal human children, who reference their 'mother' frequently and talk about how nice it is to have someone visit, revealing that others have visited on occasion but never come back after visiting once. (With such an inconvenient location, that's not surprising! But that's not the only reason.)
Their mother is finally revealed and is a distorted, harpy-like creature, abnormally tall with wings instead of arms. I don't recall the usual features of the harpy, such as stench and captivating song, being involved. The strange creature seems devoted to the children, and offers the party the use of canoes or rafts or something to travel down the river. After they take advantage of this, however, she follows them by flying and attacks with numerous flying allies, perhaps summoned creatures, attempting to kill them so she can bring them back to serve as food. For some reason, she doesn't want the children to know about this, which is why the elaborate charade of loaning them the canoes comes into play -- it's the only way to let the children think the party has left safely, so they don't associate the long pork they are subsequently unwittingly fed with their visitors.
Does this sound at all familiar to anyone, or is it maybe something I dreamed up?
Never heard of anything like this. Very kreepy and twisted. Innocent canibal children. eww.
It could be a fun set of encounters. The harpy creature might have been summoned to protect the kids while there more normal guardian went away intending to return however died the geased harpy creature is still caring for the children because it was made to, however without the guidence of the original caretaker is taking to a "by any means necessary" approach.