|Episode(s)||13.17 The Thing|
Glythur is the mate of Yokoth, who was meant to follow her through the portal, before it was closed prematurely.
After Dean finds Sandy feeding on Buck outside the diner, he is attacked and taken to the chapterhouse where Yokoth chains him to the alter and reveals to him that she plans to use him as the vessel for her mate Glythur. Yokoth performs the ritual to open the rift, which allows Glythur's tentacles enter and attack Dean as he attempts to possess him. While Dean dodges the tentacles, Sam, Ophelia, and Marco arrive and distract Yokoth. When Dean manages to free himself, he is able to steal the Seal of Solomon from Yokoth, allowing Ophelia to use it to close the portal. Just before it closes, Glythur grabs Yokoth, returning her to their universe.