Much like Riddler himself, I appear to have accidentally blabbed the answer in my own question.
The green questionmarked one does indeed appear in one of these E3 shots, along with some miniature penguins (sure, why not) and a couple of Bat-gadgets.
Batman: Arkham City is due for release this October on PC, XBox 360 and PS3.
Founder and Editor of PC Invasion. Veteran PC gamer of over 22 years.