The Batman from Planet X
From Batman #113... Batman is transported to the planet Zur-En-Arrh (also known as Planet X) where he meets this alien version of himself.
Here he meets his smiling alien counterpart, The Batman of Zur-En-Arrh! This alien Batman has been studying the exploits of Earth's Batman through a telescope(!) and has decided to be just like The Bat. Like Batman, the alien has a secret identity as "Tlano the Scientist," as well as a Batcave stocked with super-scientific gizmos such as his rocketship Batplane (strangely, this Batplane has the logo of Superman's robot sidekick "Powerman**" on it's side instead of a bat -- I guess Tlano must have been watching Powerman with his telescope, too!), and his mysterious "Bat-Radia" which "issues electronic molecules that cause controlled disturbances in the atmosphere."
The best part of this story is that on this planet, Earthlings gain super-powers, just like Kryptonians do on Earth. It turns out that Tlano needs the help of a super-powered Batman to fight off an invasion of evil aliens armed with giant robots! Afterwards, Tlano gives Batman the Bat-Radia for his trophy collection, and teleports him back to his Batplane, where Batman finds that only a few seconds have passed since he left earth, even though hours had gone by on Planet X. The story ends with a grinning Batman commenting that it all could have been a dream -- except for the fact that he now holds a Bat-Radia in his hand!
*Batman #113: "Batman - The Superman of Planet X" is reprinted in the "Batman in the Fifties" trade paperback.
**Powerman first appeared in World's Finest #94: "The Origin of the Superman-Batman Team," and is reprinted in "The Greatest Batman Stories Ever Told" trade paperback.
Copyright 2003 Atomic Robot