|Episode(s)||7.03 The Girl Next Door|
Jacob and his mother Amy Pond are kitsunes. She is working as a mortician which is where she obtains the pituitary glands they feed on. However, when he becomes sick, and only fresh brains will heal him, Amy kills three people to save him.
Sam sees details of the killings in a local paper, and examines the body of the latest victim - a drug dealer who has had part of his brain removed.
Sam tracks Amy down, and she pleads her case with him - explaining that this was an extraordinary situation: she had to save her son, and she is trying to live a normal life. Remembering that she killed her mother to save him, Sam lets her live.
After Dean catches up with him, Sam reveals the whole story. Later unbeknownst to Sam, Dean tracks Amy down and kills her. Jacob witnesses the murder from the doorway. Dean tells him if he ever kills anyone, he'll come after him. Jacob replies "The only person I'm going to kill - is you."