Eunice norvegica can grow to a length of about 20 cm (8 in), and is pink, brownish or black with some brown spotting.

The prostomium, the front-most segment, is slightly lobed and bears two eyes and five antennae.

In general, it inhabits an irregularly bent, sometimes branching, parchment-like tube partially embedded in soft sediment such as sand, muddy sand, mud, gravel, broken shell or fragments of coral.

[2] It often lives in association with deep water corals such as Lophelia pertusa.

[3] This extra growth probably strengthens the coral and at the same time provides protection for the worm.