Actually, I have to throw out
Operation Tumbler-Snapper and
Operation Buster-Jangle as candidates for the silliest
codename as well. Both of those were also series of
U.S. Atmospheric Nuclear tests.
Upshot-Knothole's first shot, called Shot ANNIE, was an 'open' shot, which meant that the press was allowed to watch from News Nob, 11 km from the shot tower. Some hold that the Government wanted to 'prove' to the American people that one could fight wars with atomic weapons without completely destroying cities. This appears to have backfired, as most of the famous images of structures and trees being destroyed that have permeated American culture through cinema and television for the past forty years are from this test series.