Wikipedia
Perchta is often identified as stemming from the same Germanic goddess as Holda and other female figures of German folklore (see Frija-Frigg). According to Jacob Grimm and Lotte Motz, Perchta is Holda's southern cousin or equivalent, as they both share the role of "guardian of the beasts" and appear during the Twelve Days of Christmas, when they oversee spinning.
Grimm says Perchta or Berchta was known "precisely in those Upper German regions where Holda leaves off, in Swabia, in Alsace, in Switzerland, in Bavaria and Austria."
According to Erika Timm, Perchta emerged from an amalgamation of Germanic and pre-Germanic, probably Celtic, traditions of the Alpine regions after the Migration Period in the Early Middle Ages.