Myling

Mylings are a type of ghost.

Characteristics
Mylings are ghosts from Scandinavian lore. They are the vengeful spirits of children who lure adults to their deaths with cries for help.

Season 12
In The Foundry, after encountering the spirit of Lucas Kellinger, Sam suspects that Lucas and the other murdered children are mylings as it seems to fit the lore. As a result, Sam and Dean salt and burn the children's bones, but their mother is able to determine that the children are not mylings and that their is another culprit.

Appearences

 * Season 12
 * The Foundry (mentioned only)