The fish become mature when about 35 mm (1.4 in) in length. It can leave the water and breathe air, exchanging both oxygen and carbon dioxide, while hiding in a damp spot, and it attempts to evade predators by flapping about or wriggling in an effort to reach a more favourable location. When the seas are rough it moves higher up the shore. Sculpins are preyed upon by diving birds and by predatory fishes when the tide is high. Small amounts of algae also form part of the diet. It is a predator, feeding on small invertebrates such as isopods, amphipods, gastropod molluscs, polychaete worms and barnacles, as well as insects that happen to fall into the water. It has been shown to have the ability to return to its home pool from a distance of 102 m (335 ft) after having been displaced for six months. It shows great homing ability, returning each time the tide recedes to the pool in which it has taken up residence. The tidepool sculpin is a common small fish in pools in the intertidal zone of rocky coasts, flitting from one hiding place to another. It is found higher up the shore and is more tolerant of warmer water than other species of sculpin such as the fluffy sculpin. It is tolerant of both brackish water and normal seawater. Its depth range is from the intertidal zone down to about 100 m (330 ft). The tidepool sculpin is found in the northeastern Pacific Ocean from the Bering Sea to southern California. It varies considerably in colour, is often marbled in grey, brown and white, but may be reddish or greenish and can change colour rapidly so as to camouflage itself.

It has a single pre-opercular spine and tufts of cirri on the top of the head but not on the body below the dorsal fin as the fluffy sculpin ( Oligocottus snyderi) does. The tidepool sculpin grows to a length of about 8 cm (3 in) and has a large head, tapering body, and spiny fins.

Tidal pool barnacle