Sculpins are mottled, broad-headed baitfish that live on the streambed of trout rivers. Big trout — 18 inches and up — eat them whenever they can. A sculpin streamer pattern (Sculpzilla, Zoo Cougar, Mike's Sculpin) imitates the profile and behavior: dragged slowly along the bottom, twitched, or swung deep through pools.
Use heavy tippet (6–10 lb) and a sink-tip line. Strip slowly with long pauses. Sculpin patterns produce some of the biggest trout caught on flies.