Start white 140 thread on an Eric SA220 streamer hook (or a shorter Gamakatsu SC15 for a stubbier profile).
Fold one strand of pearl flashabou in half and tie it in at about mid-shank as a short tail/keel of flash; secure with thread wraps.
Tie in a bunch of rainbow Flash-n-Slinky on top as the darker back, matched to the length of the tail.
Tie in a bunch of white Flash-n-Slinky underneath as the belly (olive-over-white palette, or whatever you like), keeping it the same length.
Seal the rear thread wraps with UV clear resin and cure; this is the spot that takes the abuse from a fish's teeth, so lock it well.
Add another short layer of rainbow Flash-n-Slinky on top and white underneath, each a touch shorter, to start tapering the body forward; trim materials to shape (err long, since you can always trim).
Continue building the underbody and profile forward to the head.
Whip finish, then build and color a head with UV clear resin and cure.