[6] Grimpoteuthis innominata has been collected from the Chatham Rise to the east of New Zealand, with a bathymetric range approximately 1600 to 2400 meters depth, close to the seafloor (likely demersal).

[4][5] The octopus is small, "fitting in two outstretched palms,"[3] and its colouring is dark red.

This octopus' mantle reaches 43 millimeters long, and a total length up to 156 millimeters long on the type material, it has an internal shell shaped like the letter "U".

[6][4] Some additional specimens captured since its description are somewhat larger, with a mantle length up to 77 millimeters.

[5] Its lobe-like fins and the shape of its shell help separate it from other species of Grimpoteuthis living in the Pacific Ocean.