The Obamas, and an unidentified person portraying the Easter bunny, hosted the 136th annual Easter Egg Roll on the South Lawn of the White House on Monday. (Reuters/Kevin Lamarque)

There are many federal government secrets. Area 51. JFK assassination files. Who wore the Easter bunny suit.

The plush white rabbit is an annual highlight of the White House Easter egg roll, which took over the South Lawn on Monday. Mr. Bunny showed up in some of the best photos from the event, as our Washington Post colleague Chris Cillizza highlighted here.

Spoiler alert (please, don’t let your kids read this): The White House Easter bunny is a human being in a costume. But the name of the staff member who donned the bunny suit is, at least for now, classified intelligence.

“That’s an eggscellent question,”  a White House official told the Loop late Monday after the festivities were over. “However, as in years prior, we will be keeping anonymous the identity of the White House staffer who earned the role as this year’s Easter Bunny.”

Last year, the Loop revealed several top administration officials who had played the part in previous White Houses. John E. Nidecker, an advance man for President Richard Nixon, once had the honor. Ursula Meese, wife to U.S. attorney general Edwin Meese, starred as Mrs. Bunny every year but one during President Ronald Reagan’s and President George H. W. Bush’s terms. And Fred Fielding, White House counsel for President George W. Bush, wore the costume at least once, as did Sean Spicer, now the Republican National Committee communications director.

President Bill Clinton, we reported last year, did not use staff to play the famous role. Reading between the lines, it sounds like Obama does, but whether we’ll ever know who is a mystery.

One thing is certain. Our hopes that it was Joe Biden in the bunny suit were dashed since the vice president spent Easter Monday in Ukraine.