A barracuda is a large tropical sea fish that eats other fish. a large tropical fish that eats flesh. Any of about 20 species of predaceous marine fishes (family Sphyraenidae) found in all warm and tropical regions and in some more temperate areas. Swift and powerful, barracudas are slender and have small scales, a jutting lower jaw, and a large mouth with many large, sharp teeth. They vary in size from relatively small to 4-6 ft (1.2-1.8 m) long. They are primarily fish eaters. They are popular sport fishes and are caught for food, though in certain seas they may become contaminated with a toxic substance. Bold and inquisitive, they are potentially dangerous to humans when large