A major new villain for Batman is introduced by Gardner Fox, Sheldon Moldoff and Joe Giella in Detective 334 (Dec. 64), but it isn’t the character referred to in the title.
The Grasshopper is the eponymous villain, luring Batman and Robin into a building, but immediately appearing at the base of it, stealing the Batmobile.
The Grasshopper then pulls a shipboard theft, and we get to see that he is actually two men, in identical costumes, explaining his impossible feats. Batman has also figured this out, noting slight differences in the voices.
They capture Robin, and attempt to lure Batman to his death, but he’s too smart for them. The Grasshopper(s) are thrown in prison, and never heard from again.
And then, on the last page, Batman receives a threatening call on his carphone from a man calling himself the Outsider, who was behind the Grasshopper’s attack. This mysterious villain will plague Batman for the next year and half.