It outgrows the blennies, its relatives, and may reach a length of 97 centimetres (38 in) TL[2] A low spiny dorsal fin stands along the entire back.

Along its reddish brown upper sides extend several irregular rows of small dark spots.

In thousands of hours of night diving in their habitat, we only observed one out of its burrow once, and when disturbed it returned immediately to the nearest opening.

Small, but well developed fry have been recorded from the northern parts of their range in Howe Sound in early spring, suggesting that spawning may take place in winter.

Eggs and early fry are completely unknown, suggesting the possibility that spawning may take place inside the burrow system.