Goniobranchus fidelis

Goniobranchus fidelis, also commonly known as the faithful sea slug, is a species of colourful sea slug, a dorid nudibranch, a marine gastropod mollusc in the family Chromodorididae.
The foot of the animal is cream in color; it is elongate and is almost covered by the edges of the wide mantle. The more central part of the mantle has a creamy-white area with scalloped edges, whereas the entire wide margin of the mantle is orange or red. Where the two differently coloured areas meet, there is a burgundy-colored border which varies in width from one animal to the other. Also available in plastic for self painting if desired.