Blenny, the common name of several families of fish that live among rocks and seaweed in shallow water and in tidepools of tropical and some temperate seas. The largest family consists of the combtooth blennies, named for their numerous, close-packed teeth. Combtooth blennies are scaleless and have fringed tufts of skin on their blunt foreheads. They can grow to seven inches (18 cm), but most grow to three inches (7.6 cm). Most are brown or olive, and several genera have irregularly spaced bands of various colors. They feed on small invertebrates and worms.

Combtooth blennies make up the family Blen-nidae. There are three other commonly recognized blenny families: Clinidae (scale blennies), Tripter-ygiidae (triplefin blennies), and Chaenopsidae (pike-blennies).