Though it has many names: Killer bug, Utah killer bug, UKB, crane fly larva - it's a killer fly.
This fly has accounted for a disproportionate number of fish and it's my goto searching pattern. The wool yarn body in Shetland Spindrift Oyster is incredibly buggy.
Since I caught so many Bear river cutthroat on this one fly, I thought I would showcase it again.
The folks at Tightline productions have a nice fly tying video that is featured on the Orvis site.
One of the earliest fly tying videos of the Utah Killer Bug was from Erik Ostrander of the Tenkara Guides of Utah.
I personally tie mine in different weights: unweighted, lead free wire under body, and dense tungsten underbody version in sizes 10-16. I most often fish a size 14, but many anglers fish a size 12 routinely.