Nembrotha cristata is a species of colorful sea slug, a dorid nudibranch, a marine gastropod mollusk in the family Polyceridae.
This species occurs in the tropical Indo-West Pacific Ocean.
Nembrotha cristata is a large black nembrothid that grows to at least 50 mm in length. Its body is covered with green pustules. The rhinophores and gills are black, edged in green. This species looks similar in appearance to Nembrotha yonowae.
(From Wikipedia, May 31st, 2012)