One Panel #569: That Dinosaur Looks Familiar

From "The Isle That Time Forgot" by Joseph Greene, Bob Kane, Jerry Robinson and George Roussos, Batman #10 (May 1942)

Batman fights what turns out to be a robot dinosaur? Might make a nice trophy, if only you could take it back to Gotham City and into the Bat-Cave. Wait. He has? Bruce Wayne has the means. So yes, this IS the dinosaur that's always been part of the Bat-Cave background, since you took up reading comic books.