"Two very bright lights climbed towards us from the ground. They levelled off and stayed on the tail of our plane. They were huge, bright orange lights. They stayed there for two minutes. They were under perfect control. Then they turned away from us, and the fire seemed to go out."
Reports of these lights started coming in throughout the entire world and even made their way into the news. Time magazine, in a 1945 article reported:
"If it was not a hoax or an optical illusion, it was certainly the most puzzling secret weapon that Allied fighters have yet encountered. Last week U.S. night fighter pilots based in France told a strange story of balls of fire which for more than a month have been following their planes at night over Germany. No one seemed to know what, if anything, the fireballs were supposed to accomplish. Pilots, guessing it was a new psychological weapon, named it the 'foo-fighter' ... Their descriptions of the apparition varied, but they agree that the mysterious flares stuck close to their planes and appeared to follow them at high speed for miles. One pilot said that a foo-fighter, appearing as red balls off his wing tips, stuck with him until he dove at 360 miles an hour; then the balls zoomed up into the sky."
The general theory was that either the Germans or the Japanese had some new kind of weapon they were testing, however, after the war, it was found out that the Japanese and the Germans had seen the lights as well and thought it was the Americans or the British testing a new weapon.
It is believed that the term "Foo-Fighter" came from the old 10cent comic books of Smokey Stover. Smokey was a firefighter and his fire engine was called the "Foo-Mobile" (see the license plate in the picture - it says Foo). One of the lines he says is, "Where there's foo, there's fire." Since the lights resembled little fireballs, the pilots started referring them to fighter planes known as "foo" - foo-fighters. At the time, the term "flying saucers" wasn't well known. Had it been, it's probable that the band of today would have needed a different name other than Foo-Fighters.
Some of the government reports of Foo-Fighters were released to the public. If you want to read some of these - which are pretty interesting - you can read them here.