That costume, actually, is from the 80's... I wore the same thing as a kid, and had my best haul in candy ever. The pattern was still around (you can buy it brand new I guess but it's different) so we just modded the old one and worked from there.
I sewed a skullcap inside it, so the top sat on my head... The fin kept hitting people and made a great conversation starter actually... Or drink spiller.
By the end of the night, I actually hadn't drank much at all but I was so hot I was just chilling in the corner of the 80's bar my friends and I wound up at... Was a good night.
On a Star Wars related note, the first bar where I was and they had the contest, there were a good 5 guys in Star Wars armor of various types including an ARC trooper and the toon hadn't even been out yet. That kicked ass. There was a Scout, and some others I recall... Not all together even though, just coincidentals it seemed, which was neat.
Hardest part about that costume was it basically was like a long dress in that it had no fly to take a leak. I had to pull the whole thing up and then go through the motions to pee, which made drinking not something too high on my priorities actually. That plus the fact that it was tough to maneuver in crowds, but I managed.
BTW my buddy's an orthodics guy, he makes prosthetic limbs and such... He also does make-up effects and things as a hobby for a Pittsburgh Television show called "The Its Alive Show" that airs campy crappy horror films on Saturday's. Anyway, he makes elaborate costumes for himself, such as the one he wore the year I had my sharky in those pics.
He was a devil, had fold-out wings on a pully rig system on his back that was covered by his prosthetic torso like, and he had goat-leggigngs that covered cloven-hoof boots/shoes that raised him a good 6 inches off the ground (he's already 6'5"). So with all that, he basicallyw as a behemoth demon with these elaborate wings that would unfold and looked like thin skin membranes on a skeletal frame. Freaky...
He got NO appreciation for his costume when we were out at the clubs but it wasn't complete that night so he could move better, but he did have the whole thing on at a bar out closer to where we live outside the city, and they were giving away either $400, or an old herse (sp). He won, and took the herse... It needs a little work but it's running and driveable. I want to buy it and sorta soop it up for a halloween mobile...