The Utah Killer Bug is a renowned tenkara nymph pattern, a variation on Frank Sawyer's classic 1930s Killer Bug, featuring a translucent oyster-colored Shetland wool body over hot pink thread for a subtle glow when wet, copper wire for weight, and a red head for added appeal. Designed to imitate scuds, crane fly larvae, or general bugs, its simple, grubby profile sinks quickly and triggers aggressive strikes from trout and grayling in streams, rivers, or lakes.