Several centuries ago, Katja kidnapped Hansel and his sister Gretel. A fable was made off of the story where they killed Katja by pushing her into her oven and escaped, but in truth, Katja befriended Hansel and he began working with her. When Gretel tried to escape, Katja killed her and had Hansel eat her heart. Having become evil himself by that point, Hansel gladly did so and continued to work with Katja for centuries to kidnap children so she could eat them.
By 2015, kidnapping children had become harder due to Amber Alerts and other methods of searching for kidnapped children, so Katja resorted to having Hansel use the transfiguration spell to transform adults who wouldn't be missed into children so she could eat them instead. When Rowena started stirring things up, the Grand Coven sent Katja to stop her.
Arriving in Pendelton, Oregon, Katja got a house and continued her work, with Hansel kidnapping J.P., Tina and Dean Winchester. Dean escaped and returned with Sam to kill Hansel, learning his identity and master. Altering their plan, the Winchesters tried to kill Katja with Bobby Singer's witch-killing spell, however, Hansel turned on them, disarming Sam while Katja smashed the spell. While she was distracted explaining her love for fat American children, she mentioned her affiliation with the Grand Coven and her task to "take care of" stupid Rowena.
Dean threw her off by surprising her with his knowledge of Rowena and Sam attacked her while he fought Hansel. Both were overpowered, and Katja ordered Hansel to use the hex bag to turn Sam into a child too. When Hansel reached for the hex bag, it is revealed that Dean managed to steal it during his scuffle with Hansel and used it to reverse the spell on himself and revert to his normal age. Dean then proceeded to kill Hansel and shove Katja into her own oven after stuffing the hex bag in her mouth, presumably to stop her from casting any spells, incinerating her and the hex bag.
Powers and Abilities
Katja was a powerful witch.
- Witchcraft - Being a witch, Katja is very experienced in the use of spells and hex bags.
- Transfiguration spell - Katja gave a hex bag to Hansel that could turn people from adults into children.
- Telekinesis - Katja also showed signs of telekinesis when she threw Sam Winchester against a cupboard without touching him. By reciting a spell, Rumpatur, she made Dean's witch-killing spell potion fly out of his hand and smash into a wall.
- Immortality - Katja can live for a very long time if not infinitely as Hansel revealed that she cannot be killed by an ordinary human and has been around an unknown number of centuries, long enough to have become a legend.
- Power Granting - Katja was able to grant her loyal servant Hansel immortality despite him being a regular human.
- Torture (allegedly) - Hansel showed his mutilated face as result of Katja's tortures.
- Witch-killing spell - As a witch, Katja could be killed by the witch-killing spell.
- Fire - Dean Winchester killed Katja by burning her to death in her own oven.
- Stronger witches - Since Katja was sent to kill Rowena, an extremely powerful witch, it is implied that more powerful witches can kill one another. Therefore, if there was a witch more powerful than Katja, they would be capable of killing her.
- Verbal Restraint - Katja was unable to defend her self from Dean after he gagged her mouth implying she needs to recite incantations for most of the spells.