Like a bat out of hell, aging hard rock legend Meat Loaf stormed the stage at a Mitt Romney campaign rally to declare his support for the Republican flag-bearer in the White House race.

In a town chosen as much for its evocative name -- Defiance -- as for its location in the must-win swing state of Ohio, the 65-year-old showman added his name to the small and esoteric list of celebrities backing the challenger.

"I have never been in any political agenda in my life. But I think that in 2012 this is the most important election in the history of the United States," said Meat Loaf, the burly rocker who was born as Marvin Lee Aday in 1947.

He is best known for his 1977 album "Bat out of Hell," which sold 43 million copies, and enjoyed a brief return to fame in 1993 when a single from the imaginatively titled follow-up "Bat out of Hell II" won him a Grammy.

To roars from the crowd, Meat Loaf warned "there are storm clouds coming over the United States, there are thunderstorms over Europe, there are hailstorms, and I mean major hailstorms, in the Middle East.

"I want you to know that there is one man who will stand tall in this country and fight the storm and bring the United States back to what it should be: Governor Mitt Romney," he declared.

The star's presence had not been announced in advance, and Romney was keen to milk the moment: "Meat Loaf! Meat Loaf was here, can you believe that?"

Meat Loaf then sang one of his hits, with lyrics that could apply to many political campaigns: "If it ain't real, fake it. If it ain't yours, take it. If it don't exist, you make it. If it ain't broke, break it."

Both Romney and his rival the Democratic incumbent President Barack Obama have attracted celebrity endorsements in the course of the campaign.

But, while Obama has been feted by Hollywood prince George Clooney and A-list recording artists Beyonce and Jay-Z, Romney's star power has been limited to irascible "Dirty Harry" star Clint Eastwood and fellow Mormons the Osmonds.