What do these have in common?

1. Wooly Bugger

2. Prince Nymph

3. Muddler Minnow

4. Royal Wulff

5. Sparkle Dun

6. Leech

7. Olive

8. Royal Coachman

9. Parachute Adams

10. Hare’s Ear

11. No cheating!

Hopefully the correct answer won't pop up too quickly. Creative guesses will be fun even if proven to not be correct.