The grey triggerfish has a laterally compressed and robust body, typically grey or brown in colour with lighter tones on the belly. This species is strongly territorial, particularly during the reproductive season. Males construct nests on the seabed by modifying the substrate, rearranging sediments, and actively defending the nesting site, sometimes displaying aggressive behaviour toward intruders. The species can also produce characteristic “croaking” sounds through muscle contractions associated with the swim bladder.

The grey triggerfish is valued in artisanal fisheries in both the western Mediterranean and the Atlantic Ocean. It is considered an Atlanto-Mediterranean species rather than an invasive one. Increases in its abundance in certain Mediterranean regions have been linked to rising sea temperatures and changes in habitat availability.