Strix is a paranoid and fearful individual, always ready to run away or hide. She doesn't like children and isn't one for physical contact, often disparaging Evelyn for hugging her, but she has accompanied her friends through dangerous circumstances nonetheless. Strix lacks basic manners and maintains a poor hygiene, exemplified by the collection of filthy oddities horded within her robes, including snacks which she refers to as "SnickettySnooks." She speaks in a dialect known as planar cant.
Strix was born in the town of Vallaki in Barovia to an unnamed human mother (referred to as "a lovely woman" by Lady Fiona Wachter) and an unidentified fiendish father. Lady Fiona Wachter states that "a deal was wrought to make [Strix]".
Shortly after her birth, Strix was taken by the Vistani, under orders from Madame Eva, to Sigil in order to protect her. She grew up in the Hive (the slum district of Sigil) as an orphan, and supported herself through various jobs, which have included corpse collection and working as a pastry chef. She learned to speak Infernal while in Sigil. According to Chris Perkins, Strix was raised by Gnomes.
Strix would eventually manifest sorcerer powers. She also has traveled to other planes, although she possesses no spells that allow her to cross into other planes, indicating she'd needed to use scrolls or other magic users to do so.
Eventually, her planar travels would land her on Toril, in or near the town of Daggerford. It is in Daggerford that she met the human rogue Diath Woodrow, who swore to always protect her. This occurred before Strix met the human bard Paultin Seppa, but eventually the three of them, along with the human paladin Evelyn Marthain, would form the Wafflecrew.
Strix witnessed an unidentified monster slaughter dozens of innocents, but was spared for unknown reasons. She carries some form of survivor's guilt which drives her to try to make the world a better place. But as an orphan from Sigil, she does not know her age or her surname.