A dragonfly nymph is one of the many things an olive/brown woolly bugger suggests. I have some WBs with bead chain eyes in place of a single bead or conehead and they do well -- whatever the fish takes them to be. They're a simple tie, and, in my opinion (for what it's worth), probably all that I'll ever need.

I'm a big believer in the power of suggestion (as well as woolly buggers).