Joan (played by Keisha Castle-Hughes) is a minor character from the fifth season of The Walking Dead. She appears in the episode "Slabtown".
Joan is brought into Grady Memorial Hospital in Atlanta, which is still running even after the city fell to the undead. She had supposedly been there before, forced into working there by former police lieutenant Dawn Lerner, but had managed to escape somehow. She is brought back in after being bitten by a zombie on the arm. Dawn calls in Dr. Stephen Edwards to amputate Joan's arm, but she struggles and states she would rather die, knowing full well how corrupt Dawn's system has become. Regardless, Dawn refuses to let Joan die and Dr. Edwards is forced to amputate the limb without anaesthetising Joan first, causing her tremendous agony.
Later, Beth Greene is mopping up blood in Joan's room, humming to herself. Joan wakes up, saying she likes Beth's humming. Whilst awake, Joan tells Beth that Dawn has no real control over what goes on at the hospital and that her officers have been abusing their power. She implies that one such officer, Gorman, had raped her previously and that Dawn allowed it.
Death[]
Later in the episode, Beth and Noah enact the first step of their escape plan. Whilst Noah is keeping Dawn distracted, Beth goes into Dawn's office to get the spare elevator key. Inside, she finds Joan dead on the floor. Evidently, she had committed suicide by re-opening her stitches and bleeding out. Next to Joan are the words "FUCK YOU" scratched into the floor, a message intended for Dawn and her officers.
Beth is cornered in the office by Gorman who attempts to have his way with her. What he doesn't notice, however, is that Joan has reanimated as a zombie who then gets up and attacks him. Beth takes the key and leaves the office as Joan tears out Gorman's throat and feeds on him. Beth passes Dawn in the hall and says that Gorman had gone to her office looking for her. Dawn goes to investigate, giving Beth the opportunity to enact her escape without anyone noticing. Off-screen, Dawn and her officers find the zombified Joan eating Gorman. Screams and gunshots are heard as this happens, indicating that Joan was put down, but possibly only after she killed another officer.