Thalassoma lucasanum? Also know as the Paddlefin or, preferably, the Cortez Wrasse?
If so, they get about 6" or 7" (one of the smallest Thalassoma), definitely aren't invert (shrimp, crabs) safe, but should leave corals and non-small fish alone. I would caution with other wrasses. Every bit as active as a Lunare, definitely needs a decent sized tank.