You could use something realistic like the Vlahos Sand Flea
Don't have the recipe but looks like an egg yarn body, ultra chenille legs ( burnt tips), hot tip silicone feelers, dumbbell eyes, a little flash under the butt. Here's his blog, if you're interested.
http://www.sandbarflies.com/blog/
If you're looking for something a little simpler, a Crazy Charlie, Gotcha, Bonefish Scampi, etc would probably work, too.
Regards,
Scott