This is a fan project I created. It's my interruption of what The Joker might look like in season 12 of Gotham.
Also, you will notice The Joker is standing on the Bat Signal. I imagine that in season 12 of Gotham, Bruce Wayne has finally transitioned into Batman and the signal is a nod to that. Furthermore, the VO from Gordon hints at the fact that there is some friction between himself and Batman.
Of course all the voice work from The Joker will have to be ADR'ed from Mark Hamill. As you can hear Mark's Joker laugh in this clip.
This demo is 100% CGI. I used Cinema 4D, After Effects, Photoshop, Adobe Fuse, and Unity to create all the visuals.
The face of The Joker was provided by the cool and kind people at http://www.gothampublicworks.com/