Abby Yates (full name: Abigail L. Yates) is a former professor from Kenneth P. Higgins Institute. She along with Erin Gilbert co-wrote Ghosts from Our Past: Both Literally and Figuratively: The Study of the Paranormal. She is one of the four Ghostbusters in the 2016 movie. She was also portrayed by Melissa McCarthy.
She is a serious researcher of the paranormal. She also has been known for playing practical jokes on people along with Jillian.
She had released "Ghosts from Our Past Both Literally & Figuratively: The Study of the Paranormal", which she wrote along with Erin without her permission. Her and Jillian had teamed up after a falling out with Erin. When Erin discovered that the book had been released she co-wrote with her, she demanded that Abby should take it down. Abby during that conversation found out about a lead; Aldridge Mansion Museum. She agreed to take down the book if Erin would take her and Jillian to the Museum and introduce them to Ed Mulgrave Jr.
While there, they all three witnessed a ghost that slimed Erin. The video Abby had shot of the event went viral.