Here are a couple of caddis kebari that I tied with some materials from Bud's collection.
Now that caddis are popping all over Utah, the fish are really keyed in on this fly. It works well as either a caddis larva or pupa. Since the hackle tends to pulse backward over the body, I pretty sure it gives the veiled appearance of an air bubble of an emerging caddis pupa. I like to cast if upstream and let it drink past me (dead drift or pulsing) and then let is swing below me and rise up.
Hook: Nymph hook size 14-18
Thread: 8/0 Black
Body: Quill body from a Peacock herl dyed light olive with herl removed (I colored one dark green with a permanent marker) Coat the body with UV Clear Cure Goo Fly Finish.
Hackle: 2-3 turns of a soft hackle feather (in these variations I used a Mallard flank feather and the fur from a Wolf tail)
Collar: 3-4 turns of CDC - whatever color feels right
Head: Black tungsten bead (the heads on the caddis in Utah are usually dark)
Adhesive: Clear cure goo UV resin