Valkyries

 are female servants of the gods that decide who lives and who dies on the battlefield. A valkyrie may choose to serve a particular god if she so chooses. Those who die in battle may have their spirits sent to the great hall Valhalla with the aid of a valkyrie. (Those who do not die a warrior's death are sent to Hel instead.)

Valkyries of Freyja
These Valkyries primarily serve Freyja herself. There are 12 altogether, but only 3 have been introduced in the Ragnarök manhwa thus far. Only one made her appearance in Ragnarök Online.
 * Sarah Irine
 * Zenobia Sadi Freile
 * Himmelmez
 * Randgris

Unaffiliated Valkyries

 * Sandra

Patches

 * Patch (2006 Jan. 27)
 * Monster "Valkyrie" is added in some areas of Odin's Shrine. The boss monster "Valkyrie Randgris" slave will be changed to "Valkyrie".