A good cover and a fun puzzler in Batman 177 (Dec. 65), by Finger, Moldoff and Giella.
“Numbers” Garvey is a very superstitious hood, with a love of the numbers that gave him his nickname. He stumbles into a cavern as this story opens, and two clay figures take on the shapes of Batman, becoming his willing slaves. He had been thinking about Batman at the time, which is why they adopted that form.
The little Batman becomes weak, and can only be re-energized by a diamond pressed to his head, which Garvey does, before returning the stolen gems to its hiding place. The two Batmen work well for Garvey, but he get suspicious of them.
So when the big Batman needs to be energized by a ruby, Garvey uses a fake. When the big Batman acts as if the gem is real, he has his gang knock them out. They turn out to be the Atom and the Elongated Man.
Batman and Robin are off to the side for much of this tale, though with two people in Batman costumes one hardly notices. But they were working with Batman to seek out Garvey’s hiding places for his stolen jewels. Batman and Robin burst in at the end, rescuing their friends and catching Garvey.