Mount a short-shank wet hook and start thread behind the eye; run a bed of thread back to about the 75% point.
Cut a short length of foam booby cord (or two foam cylinders) and lash it across the top of the shank just behind the eye with tight figure-eight wraps, forming a pair of large dumbbell-style foam eyes; add a drop of glue and let the eyes sit proud and prominent. They are the fly's flotation.
Carry the thread to the bend. Tie in a full marabou tail about one and a half shank-lengths long, binding the butts forward to smooth the underbody; trim the excess.
Tie in the Fritz or Ice Chenille at the bend.
Wind the chenille forward in touching turns to build a full, fuzzy body, stroking the fibers back after each wrap; stop when you reach the foam eyes.
Figure-eight a couple of chenille turns around and behind the eyes to fill the gap, then tie off tight behind the foam.
Whip finish behind the foam eyes and add a drop of cement.