He's a dude leaving behind temporary ice sculptures on the roofs. Somehow I don't think he's that hard to miss... unless Tyrus is blind or just not that perceptive. xD

There's also the fact that he's literally the only ice guy in Gotham besides Mr. Freeze. Oh well, at least I've got the Ivy stuff to work with. Going to assume Midtown isn't that far off from Devil's Square otherwise I doubt Zero could have showed up at STAR Labs as quickly as 12wave suggested in their post.