Dr. Ellen Piccolo was a character on the hospital show Dr. Sexy, M.D., and was part of the trap the Trickster created for the Winchesters.
History
Their reality altered by the Trickster, Sam and Dean found themselves in a hospital, dressed as doctors. As they were still trying to get their bearings, she approached, slapped Sam across the face and accused him of being a “brilliant coward.” When Sam asked what she was talking about, she slapped him again for acting like he didn’t know. As she stormed off, Dean recognized her as the “sexy, yet earnest” Dr. Ellen Piccolo, a character in one of his guilty pleasures, Dr. Sexy, M.D. He subsequently realized that he and Sam had somehow become part of the staff at the fictional Seattle Mercy Hospital.
After the boys sussed out the Trickster, who proceeded to trap them in TV land, Dr. Piccolo approached them again. Sam managed to duck when she attempted to give him another smack, and asked her what the hell her issue was. She tearfully told him that he was the finest cerebrovascular neurosurgeon she’d ever met, and that it wasn’t his fault he lost a patient on the operating table. Sam tried again to tell her he had no idea what she was talking about, which caused her to accuse him of being afraid to operate again, and being afraid to love. She was last seen mouthing a tearful “I love you” to Sam from outside the OR, encouraging him as he prepared to operate on gunshot-wounded Dean.