I have a Scorpion in my 37gal eclipse community tank, well, let me revise that- it was sold as a scorpion, but its actually a white-faced wasp fish and I LOVE the little guy! he has so much personality, he begs for food, perches like a goby, and doesn't mess with anyone. When he gets excited, his crest of spines goes up like a Cockatoo.
Currently he's in with a niger trigger and a small domino damsel. In the past has lived happily with a small dragon wrasse, a flame angel a volitan lion and a humu trigger.
I'll post a pic of him when I get home.
IF you can find one I really reccomend these guys, but BE CAREFUL: the small amount of info I could find said they pack a pretty good punch if ya get poked!