The finger-collecting, showtune-crooning Scarecrow in "Crimson Mist" was vaguely creepy...I'm just wary of the writers. It's hard to build up a character to be genuinely scary, as with Geoff Johns' recent Black Hand revamp, and easy to simply do something akin to that "Scarebeast" fiasco.
Who knows, maybe a new character is in order? I recall Peter Milligan try out something with a "Mistress of Fear" a few years ago...