Scampi

I've heard it described as a variant of the Gotcha, but I think that's cause the one with the most fly shop bin appeal is in similar colours to the gotcha, but there are other versions that aren't in that colour scheme. It's a good fly for when you want something with a bit more bulk but are still in the skinny water. You can, obviously weight it more heavily if you're dealing with strong tidal flow or deeper water, but I think it really work best as a beefy, ankle-shin deep option.

It's got a bit of flash, and a lot of movement. The zonker strip wing really gives a sort of elongated lozenge shape and a nice sinuous movement withot a load of appendages that I think is far more imitative of mantis shrimp than a lot of mantis specific imitations. Plus, it moves at rest, can't foul and guarantees the fly is fishing the right way up even if tied unweighted- because drag is more important than weight.

Here's the pattern
Hook: Gamakatsu SL11-3H size 6-1 (or your preffered saltwater hook)
Thread: Fluo pink Danville's Flat waxed
Weight: Beadchain or Dumbbell
Tail: Pearl mylar tubing
Body: Pearl mylar tubing
Wing: Tan rabbit zonker
Overwing: Pink Polar fiber & 2 strands of pear crystal flash

Alternatives
As above but flou orange thread & shrimp polar fiber
As above but fluo orange or blue thread, olive zonker and brown polar fiber

Basically it's up to you. Use colours representative of the crustacea where you're fishing. If you want to go weightless you can just omit the beadchain or dumbbells and you'll have a perfectly functional fly, alternatively you can add a plastic beadchain or nylon dumbbell but that's more for the look of the thing than any real effect in my opinion. I do add them but they often break off after a few fish which has no effct on the efficacy of the fly.

As I mentioned earlier, although this was devised as a bonefish fly it's absolutely killer for loads of flats species. From bones to triggers to trevally and anything in between, I'd be pretty happy walking the flats with a size 2 Bonefish Scampi on the end of my leader.