A simple but deadly trout fly pattern popular on stillwaters. Cormorant flies do not imitate a specific invertebrate but as a suggestive pattern they look like they 'should' be food! They could be a buzer, fry or even a snail.
Fished on floating lines static as a if imitating buzzer patters or retrieved with slow figure of 8 like a nymph or fly or with an intermediate or sinking fly line stripped quickly these are deadly patterns and always appear on the catch return sheets at most stillwaters. Use with an attractor pattern like blobs or boobies which often get looked at then ignored as the trout hammer the cormorant as it is more suggestive as food. Great as part of an attract and decieve rig on droppers.