The barracuda is a ray-finned fish, notable for its large size (as large as 4-6 feet) and fearsome appearance.
Barracudas are nocturnal creatures, they are swift and powerful, have small scales, and have a slender form, with two well-separated dorsal fins, and a jutting lower jaw that shows off a mouth full of many sharp teeth.
Their body is a classic example of a lie-in-wait or ambush predator.  Barracudas rely on surprise and short bursts of speed to overrun their prey. They are bold and inquisitive, and fearsome fishes, that may be dangerous to humans (remember what Marco did to Johnny?).