Yukinba likes to come out on winter nights when snow is falling. Children are not allowed outside on such nights because Yukinba may abduct them (to eat). She is presumably one-legged as she leaves a track of solo footprints.
According to the Edo Era scroll Bakemono Emaki (Monster Scroll ばけもの絵巻), a man was walking in a wheat field during a snowstorm around the 2nd month (lunisolar calendar). He heard a woman’s voice calling his name. When he looked up, he saw a one-legged old woman with messy hair hurtling towards him through the snow. He hurriedly ran away and after running for some time, the snowstorm lifted and the old woman disappeared.
In Yamagata, they say that when the Shirotsuko insect flies in late autumn, it means Yukinba is in the nearby mountains.