My grandmother. She wouldn't let my Mom call her "Mom" for the first 12 years of Mom's life for fear someone would think my grandmother was actually someone's mother. When my sister was born (the oldest grandchild), my great-grandfather blew his top when his daughter refused to be called "Bubbie" (grandmother in Yiddish) and insisted upon it.
She's been horrible to to my Mom for Mom's entire life--and she's still alive! Just turned 95yo and refused to give my Mom a 75th b-day card unless Mom drove into LA to take my grandmother here and there for errands. Mom does this twice a month, but on her birthday? Under threat?
Within a month of Dad's death, my grandmother--on Mother's Day with Mom sitting right next to her--didn't like something I said and commented, "You're just like your Father." "Thank you," I said. She said, "That's not a compliment." All I said was, "That's more of a compliment than you will ever know." She gave up then. Likely because she knew that I'm not THAT MUCH like Dad--he would never chew her out in public as I was about to if she opened her mouth again.
She has never said another derogatory word about me or Dad in my presence. To my Mom, yes; but not to me. What I would have to say to her is pretty bad. Along the lines of, "I really wish you had died instead of Dad." And yes, I really would say that to her face.
That buzzard comment reminded me of something that our mechanic said the other day over at the office. There was a lot of stuff found at our office and we've been having a garage sale to get rid of some stuff..well a stuffed-animal buzzard was found and the mechanic said: oh look, here's my ex-wife! 
