Wingworms

Wingworms are a lineage of flying binucleid worms.

Anatomy
Wingworms are unusual among fauna in that their eyes are on their abdomen. Many species fly backwards as a result. Their wings are attached to their cephalic segment. While wingworms ancestrally had many legs, eight on their cephalic segment and two on each abdominal segment, these along with their eyes have been inexplicably lost many times independently.