a joyful exclamation local to Baltimore, MD. Simply the coining of two similarly silly phrases, "beef Wellington" and "gee willickers!", through comedic pararhyme.
-"We're going to pick up the new TV."
-"Well beef willickers!"
A willicker is a cannibalistic mountain person grossly disfigured through generations of in-breeding or radiation poisoning. From movies like Wrong Turn and Hills Have Eyes.