Tess Vargas is an NYPD police homicide detective and the partner and best friend of Catherine Chandler. She knows the secret of Cat's boyfriend, Vincent. Although she wasn't always on board with Cat's choice in dating a beast, she now supports her and helps in any way she can.
Tess dated the former police chief, and now works with Gabe Lowen on special projects relating to the beast with the help of Vincent's friend J.T. Like Vincent's best friend, J.T., Tess is sarcastic and funny and will do anything for those she cares about.