COB

Cock on Balls; or COB to have completed a task in good time, or exceptionally well or built something to perfection. Derived from the male form, Cock being slang for penis and balls slang for testicals. there is no greater design or example of perfection then the male anatomy.

Ben: " hows that job commiing?"
Pete "cock on balls be done in a minute!"

"you've done another COB job johnson"