Polednice is a female character (although in the picture she’s played by male Czech actor Bolek Polívka) of Slavic folklore that haunts children. She owes her popularity to Karel Jaromír Erben, who included story about her in his collection of poems Kytice

appearance: small, pale woman with wild face (hidden under cloth), walking on crutches to support her crooked limbs, gifted by a voice that strongly resembles gale
occurrence: 11:30 - 12:30 am, hence the name Polednice from poledne = noon
hobbies: abducting small misbehaved children
other special abilities: those who see her face will never laugh again

Her distant cousin is probably Klekánice who kidnaps children that are still roaming outside after the church or chapel bell rings in the evening.