Dimoran butterflies.
A Dimoran butterfly was an otherwise unnamed animal lifeform native to Dimorus in the 23rd century.
History and specifics[]
These purple flying animals had butterfly-like spotted wings. Their slug-like bodies had two eyestalks, six appendages, and a tail ending in a ball.
In 2255, two Dimoran butterflies were seen flying near the beam-down site of a landing party from the USS Farragut. Later, four of them flew above the landing party as they tended to an injured member of a Starfleet science team. (TOS comic: "Gary")