There are over 1,320 species of fish in this order. They are found in oceans around the world, from shallow coastal waters to deep-sea environments, and are especially common in the Indo-Pacific region.

Scorpaeniformes are best known for their distinctive appearance. Many species have large heads, spiny ridges, and bony plates that give them a rough, armored look. Their bodies are often camouflaged with mottled colors, frilly skin flaps, or algae-like growths that help them blend in with rocks, coral reefs, or the seafloor. This camouflage helps them remain nearly invisible to both predators and prey.

Most species are less than 12 inches (30 cm) in length. The smallest are the velvetfishes, which can be as tiny as 0.79 inches (2 cm). The largest species is the skilfish (Erilepis zonifer), which can grow up to 6 feet (1.8 m) long.

Many fish in this order have venomous spines. Species such as scorpionfish and lionfish have sharp dorsal (top) spines connected to venom glands. These spines are used for defense, and a sting can be painful—and sometimes dangerous—to humans.

Most members of this order are carnivorous bottom-dwellers that rely on ambush hunting. They remain still, waiting for small fish or crustaceans to come close before striking quickly with their large mouths. Because of this lifestyle, they often have broad pectoral (side) fins that help them rest on or move along the ocean floor.