Teruteru Bozu
Superstitions

for further reading: Life at Maison Ikkoku

The little ghost figure hanging outside a window is called a teru-teru-bozu, a simple doll made of white paper or cloth, believed to have the magical power to bring good weather. The custom of praying to a teruteru bozu is long established in Japan, invariably associated by many Japanese people with their happy and innocent childhood days.

Relevance to Urusei Yatsura

Cherry's face happens to look just like a teruteru bozu, which is why Tsuyuko Amamori is scared to death of him, since she is being haunted by a rain demon.