Reinhardt did not explain this name but it is thought to refer to the thick, leathery illicium of this species.

[7] Himantolophis groenlandicus is sexually dimorphic with the metamorphosed females and males being very different in appearance.

They also have a wide vomer which has no teeth, well developed spines on the sphenotic bone, there is a covering of low, rounded papillae on the snout and chin and, at least in larger individuals, there are conical spines in the skin which are scattered over the head and body.

The esca of footballfishes vary in size and morphology, to a greater extent than other deep sea anglerfishes.

[4] Features which distinguish this species include the length of the illicium being equivalent to 28–54% of the standard length, the esca has a pair of truncated appendages on its tip which are shorter than the diameter of the bulb and which are surrounded by 4 swellings, there are several branched or unbranched appendages on the bulb resembling tentacles.

[14] At the depths at which these fishes live it is dark and food is sparse and rarely encountered.

The female footballfish have bioluminescent bacteria in their escas and this is used to attract prey to within striking distance of the mouth.