There's 2 types of flies called the "green weenie"
The little one with the micro chenille imitates the inch worm and is an early summer hatch
The other imitates the caddis larvae commonly called the green rock worm
Likely a Rhyacophila
They're pretty common and the ones that I tie look something like this
Size 10 or 12
Tying the Green Caddis Larva Nymph Pattern