My Story: this occurs to my old neighbour....
This happens a few years ago.. when my neighbour's daughter was pregnant with the first child when she saw that 'thing'(langsiur) outside the kitchen's window....
She saw that 'thing' flying like a swan... a very big swan indeed... but then she realise it was not a swan... she had goosebumps and she doesn't know what to do cause her leg was rooted to the ground. She tried calling her mother but her voice just couldn't come out...
She prayed hard for the safety of her baby and herself.. and that thing disappeared...
The next day she told her mother, her mother kept quiet for a moment. Her mother then consulted my other neighbour. Then the neighbour told us that what she saw is a "langsiur"