Whaddya Call Me?

There's this article about a woman whose cable bill was addressed to "Bitch Dog" and a guy whose electric company sent him letters addressed to "Scrotum Bag". Leave it to me to notice that both of these have a certain feature (and I'm sure there's a word for it that I just can't think of). It's like saying a "round circle". All bitches are dogs. All scrota are bags. All circles are round (Yes, that one's backwards but it's the same idea). Anybody know what word I'm looking for?

Update: Duh. I guess the word is "redundant" but I was hoping for something more elegant.