In a refreshing twist, the unsub is revealed to be a woman, (played by Doris Morgado). Desi’s rage is fueled by a deep-seated "mother wound." Her mother, Laura, a successful realtor, was physically and emotionally abusive, famously locking Desi in a shed with snakes as a child.
The unsub subdues victims using venom from an Eastern Brown Snake , which incapacitates them without killing them. [S13E7] Dust and Bones
The BAU identifies the mask as a symbol for peeling away the "fake" public personas of the victims to reveal the "monster" underneath. The Unsub: Desi Gutierrez In a refreshing twist, the unsub is revealed