Sawyer's Killer Bug Barbless is Frank Sawyer's simple, suggestive river nymph. The original was devised around Chadwick's 477 yarn and is commonly interpreted as freshwater shrimp, caddis larva or another compact, protein-rich food item rather than one exact insect.
Dead-drift it close to the riverbed for trout and grayling, using enough leader control to detect takes without pulling the fly unnaturally. It works beneath an indicator, in a short-line nymph setup or as part of a team. Its deliberately plain profile is central to the pattern's versatility. Its profile and movement make it a strong choice for turning a quiet drift into a take.