Plocamopherus pecoso is a species of sea slug, a nudibranch, a shell-less marine gastropod mollusk in the family Polyceridae.

The head bears a fringed oral veil with eight short, small and ramified appendages.

Plocamopherus pecoso has a transparent white background color heavily speckled all over the body with small orange dots.

There are some white dots that are usually situated on the notum along a non-continuous line at the margin of both sides of the animal and joining behind the branchial gills.

The posterior portion of the foot forms a well-developed keel that has a small crest tipped with white.