Season 11: Nicole Herman
In season 11, Arizona becomes the student of fetal surgeon Nicole Herman (Geena Davis). When Dr. Herman reveals to Arizona that she has an inoperable tumor and six months left to live, she more or less exports all of her knowledge to the peds surgeon. Amelia, of course, finds a way to operate on her brain. Though the surgery renders her blind, she lives on and eventually recruits Arizona years later for a clinic idea.