Erica Hahn is a character from the popular medical drama television series 'Grey's Anatomy'. She is portrayed by actress Brooke Smith and was introduced in the second season as an attending cardiothoracic surgeon at Seattle Grace Hospital. ERICA is a strong-willed, no-nonsense doctor who often clashes with the other characters due to her blunt attitude and her tendency to speak her mind. She eventually leaves the hospital after a disagreement with Miranda Bailey, but returns in later seasons as a mentor to some of the younger doctors.