Tom King revealed that The Phantasm from the animated movie Mask of the Phantasm will appear in his Bat/Cat coming series. The Phantasm first appears in Batman Mask of the Phantasm #1 in 1993 followed by an appearance in Batman and Robin Adventures Annual #1 in 1996, there’s also a nice cover for Batman Beyond #20 vol 2
Ive heard that the same cover image, w/ the Phantasm on it, was briefly put up on DCs retailers forum before it was promptly removed. DC then said the image was not ‘real’. However, King still has the image up on his instagram.