Earlier today, I noted how it was surprising how relatively quite recent the addition of Batman vanishing on Commissioner Gordon was to the Batman mythos, coming in 1973 in the pages of Swamp Thing, of all places.

So I figured I'd feature some other surprisingly relatively quite recent additions to the Batman mythos, things you figure must have been around much earlier than they actually became part of the Batman mythos.

It was not until 1969's Batman #216 that Alfred first got the name Pennyworth...

It was not until 1974 that Arkahm Asylum first showed up in Batman #258...

(As you can see, Two-Face was the first Bat-villain to escape from Arkham)

It was not until 1976's Detective Comics #457 that the area where Bruce Wayne's parents were murdered was dubbed "Crime Alley" (it was also the first appearance of Leslie Thompkins, but that's not all that surprising)...

It was not until 1986's The Dark Knight Returns that Martha Wayne's pearl necklace broke...

It was not until 1972 that Matches Malone first showed up in Batman #242...

He dies in that issue...

And the Matches Malone identity began to be used later in that same issue...

(the Batman in the scene is a dummy equipped with a radio transmitter - Bat-Ventriloquism would have been cooler, no?)

Can you think of any other interesting examples of surprisingly relatively quite recent additions to the Batman mythos? There's a good one involving Alfred that I'm holding off for a different feature, so if you don't mind, please don't suggest any examples involving Alfred.