Plocamopherus margaretae is a species of sea slug, a nudibranch, a shell-less marine gastropod mollusk in the family Polyceridae.
Plocamopherus margaretae has a pink or red background color heavily speckled all over the body with large white spots and black, almost oval spots.
The rhinophoral sheath is the same background color as the body and is short with its margin lined by white and yellow pigment.
There are three pairs of lateral appendages, which are rounded and form prominent globular structures.
The posterior portion of the foot forms a well-developed elongated keel that is slightly fringed in its upper margin.