A lot of famous bands went by a different name before they got famous. For example, the Beatles used to be called The Quarrymen. But there are many more examples.
Van Halen started out as Genesis, but of course that name was already taken. They also went by Mammoth early on.
Pink Floyd went through several bizarre names like The Tea Set, The Abdabs, The Spectrum 5, and Sigma 6.
Foreigner used to be called Trigger, Queen were known as Smile before they met Freddie Mercury, and Def Leppard were once known as Atomic Mass.