The model consists of a low poly base mesh driving a high poly proxy mesh. With the free plugin in Connect Poly Shape you can thus change the tesselation of the proxy mesh to fit your need, while beeing able to animate the low poly mesh in real time.
Materials are included. The fur is attached to the low poly mesh. If not needed, the butterfly looks fine without the fur. See last preview pic.
Material and fur settings are set up for rendering with mental ray. Included prewiev pics are made with mental ray. (But be warned, rendering fur in mental ray takes some time. I advise on rendering the fur in a seperate pass. Background and environment are not included in file. Be sure to use a nice environment, i.e. hdri map, to get some nice reflections and highlights onto the butterfly, esp. the body and eyes rely on it to look good.)
The butterfly is rigged and ready for easy animation with few control objects.
See attached Quicktime for a quick flyaround.