The tompot is a favourite fish of many divers because of its clown like face, with big lips and prominent eyes. It is large and stout, for a blenny, commonly up to 20cm long. One of the most distinctive characteristics of the tompot, are the two branched head tentacles, which are located above the eyes. It has a long dorsal fin which is separated into two halves by a shallow notch. The front half of the fin has stiff, spiny rays whilst the back half is made up of soft rays. Apart from the shallow notch separating the front and back half, the fin is the same height overall. The colour is mottled brown or brownish red with seven or more darker bars running across the sides.
The Tompot Blenny is usually found in holes, on rocky ledges or amongst boulders and seaweeds at depths down to approximately 20m in the inshore Cork dive sites. The tompot blenny is common on the south, and west Ireland
The Tompot is an inquisitive little fish and can easily be approached if no sudden movements are made. They appear to be more active at dawn and dusk. They are very territorial. Underwater photographers are big fans of the tompot because of its habit of posing popped up on its pelvic fins.