A group of barracudas is called a battery, a term that likely nods to their sudden, high-voltage bursts of speed and aggression when hunting. Barracudas are streamlined, torpedo-shaped predators known for explosive short-distance speed, using ambush tactics to strike prey with startling suddenness rather than sustained chases.
Juvenile barracudas are considerably more social than adults, forming schools for protection against larger predators. As barracudas mature, most species shift toward a more solitary lifestyle, though some, like the great barracuda, are still occasionally seen in loose groups near reefs and wrecks.
Bonus fact: barracudas have a reputation for aggression toward humans that’s largely undeserved, most documented incidents involve the fish mistaking shiny jewelry or dive gear for the flash of a baitfish, not a deliberate attack.
Barracudas are also sometimes grouped under general fish terms like a school when referring to younger, more social individuals.
Related: Collective Nouns for Fish