They're noisy and they're scary. And they come every year.
Masked devils march through the village, rattling their chains and clanking bells, going door-to-door to search for badly-behaved children.
The sinister-looking pre-Christmas tradition in the Czech village of Valasska Polanka is actually a celebration of the 4th-century Saint Nicholas, who appears in costume to soothe the children with sweets.
For the residents in the village, 330 kilometres southeast of the capital Prague, being chased in the snow by 40 fearsome figures in sheepskin masks is all part of the fun and a long-held tradition.
"The tradition is long-standing, beautiful and you can't find it anywhere else but in southern Moravian Wallachia. It's very specific, as you can see, and I like it very much," said local resident Petr Filgas.
One of the devils, who called himself Cerny Cert or Dark Devil, said the 40-year-old mask he wore was once used by his father.
This tradition is repeated in other villages around the region in the run-up to Christmas Day.