To quote from "Dick Deadeye, or, Duty Done" (1975) (art by Ronald Searle)
"I'm called Little Buttercup, Dear Little Buttercup
Which I would much rather not;
But Ma called me Buttercup, Pa called me Buttercup,
Parents like that should be shot..."

I think Miriam Karlin provided the voice but I wonder ....*checks http://www.imdb.com *
YES it was. I bet you've never seen her in "the Rag Trade"
*PWEEEP* - EVERYBODY OUT!!!!