Ameonna is a female spirit illustrated in Toriyama Sekien's Konjaku Hyakki Shūi

Konjaku Hyakki Shui

is the third book of Japanese artist Toriyama Sekien's Gazu Hyakki Yakō series, published ca. 1781. These books are supernatural bestiaries, collections of ghosts, spirits, spooks and monsters, many of which Toriyama based on literature, folklore, and other artwork...

 as a woman standing in the rain and licking her hand. She is described as a goddess from China's Mount Wushan, who is a cloud in the morning and rain in the evening. She may be considered a rain-bringer for crops.

In modern usage in Japan, "ameonna" (or the male equivalent "ameotoko") refers to an unlucky person that seems to be jinxed to have the rain follow them wherever they may go, thus gaining a reputation for ruining special events such as weddings or sporting events.