Soul Piper

The Tatarimokke (タタリモッケ) or "Soul Piper" in the English dub, is a demon who was born from the souls of dead children. It plays a flute and plays with the child(ren) until it is ready to go to either heaven or hell. The eyes are usually closed, but each time a certain soul does wrong, such as Mayu's case, the Soul Piper's eyes open a bit more. When its eyes have opened completely, the Soul Piper wraps the soul of the child in chains and takes it to the place of its death, where a vortex opens and the soul is pulled by the chains into the depths of hell.

Kagome calls it a poltergeist, or ghost. She goes in it to save a child, Mayu, who thanks her. She almost went to hell herself! Only humans can enter this vortex, thus Inuyasha couldn't go near the portal to hell because he is half demon. Because of how Mayu had a change of heart, in regards to her mother and brother, in the last minute the Soul Piper had changed his judgement.